Lubricating oil compositions with engine wear protection

ABSTRACT

A method for improving wear control, while maintaining or improving fuel efficiency, in an engine or other mechanical component lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and a mixture as a minor component of (i) at least one metal salt of a straight chain carboxylic acid, wherein the metal is selected from the group consisting of palladium (Pd), silver (Ag), gold (Au), zinc (Zn), and combinations thereof, and (ii) at least one metal salicylate salt, wherein the metal is calcium (Ca), magnesium (Mg) or combinations thereof, wherein the molar ratio of the total metal concentration from the salicylate salt divided by the total metal concentration from the straight chain carboxylic acid ranges from 0.1 to 40. The lubricating oils are useful in internal combustion engines.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-in-Part application and claimspriority to pending U.S. application Ser. No. 14/979,719 filed on Dec.28, 2015, the entirety of which is incorporated herein by reference,which claims priority to U.S. Provisional Application Ser. No.62/097,661 filed Dec. 30, 2014, which is herein incorporated byreference in its entirety. This application is also related toco-pending U.S. application Ser. No. 14/979,773 filed on Dec. 28, 2015and identified by the following Attorney Docket number and title:2015EM245-US2 also entitled “Lubricating Oil Compositions with EngineWear Protection.” This application is also related to co-pending U.S.application filed on the same date and identified by the followingAttorney Docket number and title: 2015EM391-US3 also entitled“Lubricating Oil Compositions with Engine Wear Protection.”

FIELD

This disclosure relates to a method for improving wear control, whilemaintaining or improving fuel efficiency, in an engine or othermechanical component lubricated with a lubricating oil by including amixture of at least one transition metal salt of a carboxylic acid(e.g., zinc stearate) and at least one detergent (i.e., an alkali metalor alkaline earth metal salt of an organic acid (e.g., calciumsalicylate), in the lubricating oil. The lubricating oils of thisdisclosure are useful in internal combustion engines.

BACKGROUND

A major challenge in engine oil formulation is simultaneously achievingwear and deposit control, and oxidation stability, while alsomaintaining fuel economy performance, over a broad temperature range.

Lubricant-related wear control is highly desirable due to increasing useof low viscosity engine oils for improved fuel efficiency. Asgovernmental regulations for vehicle fuel consumption and carbonemissions become more stringent, use of low viscosity engine oils tomeet the regulatory standards is becoming more prevalent. At the sametime, lubricants need to provide a substantial level of durability andwear protection due to the formation of thinner lubricant films duringengine operation. As such, use of antiwear additives and frictionmodifiers in a lubricant formulation is the typical method for achievinglow friction, wear control and durability. Due to limitations of usinghigh levels of some antiwears due to catalyst poisoning and depositformation, it is highly desirable to find alternative methods forachieving excellent wear control and durability without poisoning thecatalyst.

Most current antiwear additives contain phosphorus and/or sulfur. Zincdialkyl dithiophosphate (ZDDP) is a common antiwear additive used inengine lubricants. However, these elements are known to harm catalystsused to treat exhaust gases from internal combustion engines, and thusantiwear additives which are free of sulfur and phosphorus will beadvantaged in the marketplace.

Despite advances in lubricant oil formulation technology, there exists aneed for an engine oil lubricant that effectively improves wear controlwhile maintaining or improving fuel efficiency. In addition, thereexists a need for an engine oil lubricant that effectively improves wearcontrol while maintaining or improving deposit control, oxidationstability and fuel efficiency.

SUMMARY

This disclosure relates in part to a method for improving wear control,while maintaining or improving fuel efficiency, in an engine or othermechanical component lubricated with a lubricating oil by including amixture of at least one transition metal salt of a carboxylic acid(e.g., zinc stearate) and at least one detergent (i.e., an alkali metalor alkaline earth metal salt of an organic acid (e.g., calciumsalicylate), in the lubricating oil. The lubricating oils of thisdisclosure are useful in internal combustion engines.

In an embodiment, wear control is improved and deposit control,oxidation stability and fuel efficiency are maintained or improved ascompared to wear control, deposit control, oxidation stability and fuelefficiency achieved using a lubricating oil containing a minor componentother than the (i) at least one transition metal salt of a carboxylicacid or (ii) the mixture of at least one transition metal salt of acarboxylic acid and at least one alkali metal or alkaline earth metalsalt of an organic acid, or at least one alkali metal or alkaline earthmetal salt of an inorganic acid, or at least one alkali metal oralkaline earth metal salt of a phenol, or mixtures thereof.

This disclosure also relates in part to a method for improving wearcontrol, while maintaining or improving fuel efficiency, in an engine orother mechanical component lubricated with a lubricating oil by using asthe lubricating oil a formulated oil. The formulated oil has acomposition comprising a lubricating oil base stock as a majorcomponent; and at least one metal salt of a carboxylic acid, as a minorcomponent. The metal salt of the carboxylic acid contains no sulfur orphosphorus. The metal is selected from a transition metal and mixturesthereof. The carboxylic acid is selected from an aliphatic carboxylicacid, a cycloaliphatic carboxylic acid, an aromatic carboxylic acid, andmixtures thereof. Wear control is improved and fuel efficiency ismaintained or improved as compared to wear control and fuel efficiencyachieved using a lubricating oil containing a minor component other thanthe at least one metal salt of a carboxylic acid.

In an embodiment, wear control is improved and deposit control,oxidation stability and fuel efficiency are maintained or improved ascompared to wear control, deposit control, oxidation stability and fuelefficiency achieved using a lubricating oil containing a minor componentother than the at least one metal salt of a carboxylic acid.

This disclosure further relates in part to a method for improving wearcontrol, while maintaining or improving fuel efficiency, in an engine orother mechanical component lubricated with a lubricating oil by using asthe lubricating oil a formulated oil. The formulated oil has acomposition comprising a lubricating oil base stock as a majorcomponent; and a mixture of (i) at least one metal salt of a carboxylicacid, and (ii) at least one metal salt of an organic acid, or at leastone metal salt of an inorganic acid, or at least one metal salt of aphenol, or mixtures thereof, as minor components. For the at least onemetal salt of a carboxylic acid, the metal is selected from a transitionmetal and mixtures thereof, and the carboxylic acid is selected from analiphatic carboxylic acid, a cycloaliphatic carboxylic acid, an aromaticcarboxylic acid, and mixtures thereof. For the at least one metal saltof an organic acid, the at least one metal salt of an inorganic acid,the at least one metal salt of a phenol, or mixtures thereof, the metalis selected from an alkali metal, an alkaline earth metal, and mixturesthereof, and the organic or inorganic acid is selected from an aliphaticorganic or inorganic acid, a cycloaliphatic organic or inorganic acid,an aromatic organic or inorganic acid, and mixtures thereof. Wearcontrol is improved and fuel efficiency is maintained or improved ascompared to wear control and fuel efficiency achieved using alubricating oil containing minor components other than the mixture of(i) the at least one metal salt of a carboxylic acid, and (ii) the atleast one metal salt of an organic acid, or the at least one metal saltof an inorganic acid, or the at least one metal salt of a phenol, ormixtures thereof.

In an embodiment, wear control is improved and deposit control,oxidation stability and fuel efficiency are maintained or improved ascompared to wear control, deposit control, oxidation stability and fuelefficiency achieved using a lubricating oil containing minor componentsother than the mixture of (i) the at least one metal salt of acarboxylic acid, and (ii) the at least one metal salt of an organicacid, or the at least one metal salt of an inorganic acid, or the atleast one metal salt of a phenol, or mixtures thereof.

This disclosure yet further relates in part to a lubricating oil (e.g.,lubricating engine oil) having a composition comprising a lubricatingoil base stock as a major component, and at least one metal salt of acarboxylic acid, as a minor component. The metal salt of the carboxylicacid contains no sulfur or phosphorus. The metal is selected from atransition metal and mixtures thereof. The carboxylic acid is selectedfrom an aliphatic carboxylic acid, a cycloaliphatic carboxylic acid, anaromatic carboxylic acid, and mixtures thereof. Wear control is improvedand fuel efficiency is maintained or improved as compared to wearcontrol and fuel efficiency achieved using a lubricating oil containinga minor component other than the at least one metal salt of a carboxylicacid.

In an embodiment, wear control is improved and deposit control,oxidation stability and fuel efficiency are maintained or improved ascompared to wear control, deposit control, oxidation stability and fuelefficiency achieved using a lubricating oil containing a minor componentother than the at least one metal salt of a carboxylic acid.

This disclosure also relates in part to a lubricating oil (e.g.,lubricating engine oil) having a composition comprising a lubricatingoil base stock as a major component, and a mixture of (i) at least onemetal salt of a carboxylic acid, and (ii) at least one metal salt of anorganic acid, or at least one metal salt of an inorganic acid, or atleast one metal salt of a phenol, or mixtures thereof, as minorcomponents. For the metal salt of a carboxylic acid, the metal isselected from a transition metal and mixtures thereof, and thecarboxylic acid is selected from an aliphatic carboxylic acid, acycloaliphatic carboxylic acid, an aromatic carboxylic acid, andmixtures thereof. For the at least one metal salt of an organic acid,the at least one metal salt of an inorganic acid, the at least one metalsalt of a phenol, or mixtures thereof, the metal is selected from analkali metal, an alkaline earth metal, and mixtures thereof, and theorganic or inorganic acid is selected from a sulfur-containing acid, acarboxylic acid, a phosphorus-containing acid, and mixtures thereof.Wear control is improved and fuel efficiency is maintained or improvedas compared to wear control and fuel efficiency achieved using alubricating oil containing minor components other than the mixture of(i) the at least one metal salt of a carboxylic acid, and (ii) the atleast one metal salt of an organic acid, or the at least one metal saltof an inorganic acid, or the at least one metal salt of a phenol, ormixtures thereof.

In an embodiment, wear control is improved and deposit control,oxidation stability and fuel efficiency are maintained or improved ascompared to wear control, deposit control, oxidation stability and fuelefficiency achieved using a lubricating oil containing minor componentsother than the mixture of (i) the at least one metal salt of acarboxylic acid, and (ii) the at least one metal salt of an organicacid, or the at least one metal salt of an inorganic acid, or the atleast one metal salt of a phenol, or mixtures thereof.

This disclosure further relates in part to a method for reducing sulfurand phosphorus and their harmful side effects of exhaust catalystpoisoning and increased corrosivity in an engine or other mechanicalcomponent lubricated with a lubricating oil by including (i) at leastone transition metal salt of a carboxylic acid (e.g., zinc stearate) or(ii) a mixture of at least one transition metal salt of a carboxylicacid (e.g., zinc stearate) and at least one detergent (i.e., an alkalimetal or alkaline earth metal salt of an organic acid (e.g., calciumsalicylate), or an alkali metal or alkaline earth metal salt of aninorganic acid (e.g., magnesium sulfonate), or an alkali metal oralkaline earth metal salt of a phenol, or mixtures thereof), in thelubricating oil.

This disclosure yet further relates in part to a low sulfur, lowphosphorus lubricating oil (e.g., lubricating engine oil) having acomposition comprising a lubricating oil base stock as a majorcomponent, and (i) at least one transition metal salt of a carboxylicacid (e.g., zinc stearate) or (ii) a mixture of at least one transitionmetal salt of a carboxylic acid (e.g., zinc stearate) and at least onedetergent (i.e., an alkali metal or alkaline earth metal salt of anorganic acid (e.g., calcium salicylate), or an alkali metal or alkalineearth metal salt of an inorganic acid (e.g., magnesium sulfonate), or analkali metal or alkaline earth metal salt of a phenol, or mixturesthereof), as a minor component.

This disclosure further relates to a method for improving wear control,while maintaining or improving fuel efficiency, in an engine or othermechanical component lubricated with a lubricating oil by using as thelubricating oil a formulated oil, said formulated oil having acomposition comprising a lubricating oil base stock as a majorcomponent; and a mixture as a minor component of (i) at least one metalsalt of a straight chain carboxylic acid, wherein the metal is selectedfrom the group consisting of palladium (Pd), silver (Ag), gold (Au),zinc (Zn), and combinations thereof, and (ii) at least one metalsalicylate salt, wherein the metal is calcium (Ca), magnesium (Mg) orcombinations thereof. The molar ratio of the total metal concentrationfrom the salicylate salt divided by the total metal concentration fromthe straight chain carboxylic acid in the formulated oil ranges from 0.1to 40, which improves wear control while maintaining or improving fuelefficiency as compared to wear control and fuel efficiency achievedusing a lubricating oil containing a minor component other than themixture of the at least one metal salt of a straight chain carboxylicacid and the at least one metal salicylate salt.

This disclosure further relates to a lubricating oil having acomposition comprising a lubricating oil base stock as a majorcomponent; and a mixture as a minor component of (i) at least one metalsalt of a straight chain carboxylic acid, wherein the metal is selectedfrom the group consisting of palladium (Pd), silver (Ag), gold (Au),zinc (Zn), and combinations thereof, and (ii) at least one metalsalicylate salt, wherein the metal is calcium (Ca), magnesium (Mg) orcombinations thereof. The molar ratio of the total metal concentrationfrom the salicylate salt divided by the total metal concentration fromthe straight chain carboxylic acid in the formulated oil ranges from 0.1to 40, which improves wear control while maintaining or improving fuelefficiency as compared to wear control and fuel efficiency achievedusing a lubricating oil containing a minor component other than themixture of the at least one metal salt of a straight chain carboxylicacid and the at least one metal salicylate salt.

It has been surprisingly found that, in accordance with this disclosure,improvements in wear control are obtained while maintaining or improvingfuel efficiency in an engine or other mechanical component lubricatedwith a lubricating oil, by including a mixture of at least onetransition metal salt of a carboxylic acid and at least one alkali metalor alkaline earth metal salt of an organic acid, in the lubricating oil.The mixture of at least one transition metal salt of a carboxylic acidand at least one alkali metal or alkaline earth metal salt of an organicacid affords greater improvements in wear control, while maintaining orimproving fuel efficiency, even over the at least one transition metalsalt of a carboxylic acid.

Further, it has been surprisingly found that, in accordance with thisdisclosure, improvements in wear control are obtained while maintainingor improving deposit control, oxidation stability and fuel efficiency inan engine or other mechanical component lubricated with a lubricatingoil, by including a mixture of at least one transition metal salt of acarboxylic acid and at least one alkali metal or alkaline earth metalsalt of an organic acid in the lubricating oil. The mixture of at leastone transition metal salt of a carboxylic acid and at least one alkalimetal or alkaline earth metal salt of an organic acid affords greaterimprovements in wear control, while maintaining or improving depositcontrol, oxidation stability and fuel efficiency, even over the at leastone metal salt of a carboxylic acid.

Furthermore, it has been surprisingly found that in accordance with thisdisclosure, improvements in wear control are obtained while maintainingor improving fuel efficiency in an engine or other mechanical componentlubricated with a lubricating oil, by including a lubricating oil basestock as a major component; and a mixture as a minor component of (i) atleast one metal salt of a straight chain carboxylic acid, wherein themetal is selected from the group consisting of palladium (Pd), silver(Ag), gold (Au), zinc (Zn), and combinations thereof, and (ii) at leastone metal salicylate salt, wherein the metal is calcium (Ca), magnesium(Mg) or combinations thereof. The molar ratio of the total metalconcentration from the salicylate salt divided by the total metalconcentration from the straight chain carboxylic acid in the formulatedoil ranges from 0.1 to 40.

Other objects and advantages of the present disclosure will becomeapparent from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (top) shows High Frequency Reciprocating Rig (HFRR) testingresults of a partial formulation in which ZDDP and friction modifierswere removed (“Partial Formulation”). FIG. 1 (bottom) shows HFRR testingresults for a “Full Formulation” which contains ZDDP and frictionmodifiers. FIG. 1 (top and bottom) contain three lines. Each line is adepth profile of the final wear scar across the center, right and leftof the oval shaped scar.

FIG. 2 shows the HFRR wear scar data generated when zinc stearate wasadded to the “Partial Formulation”. The three lines represent depthprofiles of the final wear scar in the center, right and left of thescar.

FIG. 3 shows the results of HFRR testing for other metal carboxylatesalts added to the “Partial Formulation” in addition to zinc stearate inFIG. 2. Results for the “Full Formulation” are also shown for reference.Some results are averages over several experiments.

FIG. 4 shows average friction results versus the ratio of moles ofdetergent metal (Ca, Mg) divided by the total moles of zinc from zincstearate for both salicylate (inventive) and sulfonate detergents(comparative).

FIG. 5 shows average wear results versus the ratio of moles of detergentmetal (Ca, Mg) divided by the total moles of zinc from zinc stearate forboth salicylate detergents (inventive) and sulfonate detergents(comparative). The wear is measured as the average of the maximum depthof three profiles taken on the final wear scar in the center, right andleft of the scar.

DETAILED DESCRIPTION

All numerical values within the detailed description and the claimsherein are modified by “about” or “approximately” the indicated value,and take into account experimental error and variations that would beexpected by a person having ordinary skill in the art. The phrase “majoramount” or “major component” as it relates to components included withinthe lubricating oils of the specification and the claims means greaterthan or equal to 50 wt. %, or greater than or equal to 60 wt. %, orgreater than or equal to 70 wt. %, or greater than or equal to 80 wt. %,or greater than or equal to 90 wt. % based on the total weight of thelubricating oil. The phrase “minor amount” or “minor component” as itrelates to components included within the lubricating oils of thespecification and the claims means less than 50 wt. %, or less than orequal to 40 wt. %, or less than or equal to 30 wt. %, or greater than orequal to 20 wt. %, or less than or equal to 10 wt. %, or less than orequal to 5 wt. %, or less than or equal to 2 wt. %, or less than orequal to 1 wt. %, based on the total weight of the lubricating oil. Thephrase “essentially free” as it relates to components included withinthe lubricating oils of the specification and the claims means that theparticular component is at 0 weight % within the lubricating oil, oralternatively is at impurity type levels within the lubricating oil(less than 100 ppm, or less than 20 ppm, or less than 10 ppm, or lessthan 1 ppm). The phrase “other lubricating oil additives” as used in thespecification and the claims means other lubricating oil additives thatare not specifically recited in the particular section of thespecification or the claims. For example, other lubricating oiladditives may include, but are not limited to, an anti-wear additive,antioxidant, detergents, dispersant, pour point depressant, corrosioninhibitor, metal deactivator, seal compatibility additive, anti-foamagent, inhibitor, anti-rust additive, friction modifier and combinationsthereof.

It has now been found that improved wear control can be attained, whilefuel efficiency is unexpectedly maintained or improved, in an engine orother mechanical component lubricated with a lubricating oil by using asthe lubricating oil a formulated oil that has a mixture of at least onetransition metal salt of a carboxylic acid and at least one alkali metalor alkaline earth metal salt of an organic acid, in the lubricating oil.The formulated oil preferably comprises a lubricating oil base stock asa major component, and a mixture of (i) at least one transition metalsalt of a carboxylic acid and (ii) at least one alkali metal or alkalineearth metal salt of an organic acid, as minor components. Thelubricating oils of this disclosure are particularly advantageous aspassenger vehicle engine oil (PVEO) products.

In an embodiment, wear control is improved and deposit control,oxidation stability and fuel efficiency are maintained or improved ascompared to wear control, deposit control, oxidation stability and fuelefficiency achieved using a lubricating oil containing minor componentsother than the mixture of at least one transition metal salt of acarboxylic acid and the at least one alkali metal or alkaline earthmetal salt of an organic acid, as minor components.

In one form, the inventive lubricating oils include a lubricating oilbase stock as a major component; and a mixture as a minor component of(i) at least one metal salt of a straight chain carboxylic acid, whereinthe metal is selected from the group consisting of palladium (Pd),silver (Ag), gold (Au), zinc (Zn), and combinations thereof, and thestraight chain carboxylic acid is stearic acid, palmitic acid orcombinations thereof, and (ii) at least one metal salicylate salt,wherein the metal is calcium (Ca), magnesium (Mg) or combinationsthereof. The molar ratio of the total metal concentration from thesalicylate salt divided by the total metal concentration from thestraight chain carboxylic acid ranges from 0.1 to 40. The inventivelubricating oils provide improved wear control and fuel efficiency isimproved or maintained as compared to wear control and fuel efficiencyachieved using a lubricating oil containing a minor component other thanthe mixture of the at least one metal salt of a straight chaincarboxylic acid and the at least one metal salicylate salt.

For the inventive lubricating oils of this disclosure, the molar ratioof the total metal concentration from the salicylate salt divided by thetotal metal concentration from the straight chain carboxylic acid mayalternatively range from 0.2 to 30, or from 0.3 to 20, or from 0.4 to10, or from 0.5 to 5. The method to measure the elements included in thetable for low phosphorus content uses an inductively coupled plasma(ICP) technique according to ASTM D5185. The results are obtained in ppmby weight. The molar Zn/P ratios were calculated using the atomic weightof zinc and phosphorus of 65.38 and 30.97 g/mole respectively.

The instant disclosure also provides a method for improving wearcontrol, while maintaining or improving fuel efficiency, in an engine orother mechanical component lubricated with a lubricating oil by using asthe lubricating oil a formulated oil, said formulated oil having acomposition comprising a lubricating oil base stock as a majorcomponent; and a mixture as a minor component of (i) at least one metalsalt of a straight chain carboxylic acid, wherein the metal is selectedfrom the group consisting of palladium (Pd), silver (Ag), gold (Au),zinc (Zn), and combinations thereof, and the straight chain carboxylicacid is stearic acid, palmitic acid or combinations thereof, and (ii) atleast one metal salicylate salt, wherein the metal is calcium (Ca),magnesium (Mg) or combinations thereof. The molar ratio of the totalmetal concentration from the salicylate salt divided by the total metalconcentration from the straight chain carboxylic acid ranges from 0.1 to40, or 0.2 to 30, or 0.3 to 20, or 0.4 to 10, or 0.5 to 5. Using themethod, the wear control is improved and fuel efficiency is maintainedor improved as compared to wear control and fuel efficiency achievedusing a lubricating oil containing a minor component other than themixture of the at least one metal salt of a straight chain carboxylicacid and the at least one metal salicylate salt.

The lubricating oils of this disclosure including a metal salt of acarboxylic acid that contains no sulfur or phosphorus means that themetal salt of a carboxylic acid is essentially free of sulfur andphosphorus. Essentially free for the purpose of the sulfur andphosphorus level in the metal salt of a carboxylic acid means that thesulfur and phosphorus is at 0 weight % within the metal salt of thecarboxylic acid, or alternatively are at impurity type levels within themetal salt of the carboxylic acid (less than 100 ppm, or less than 20ppm, or less than 10 ppm, or less than 1 ppm).

In addition, the lubricating oils of this disclosure can be useful ascommercial vehicle engine oil products (e.g., heavy duty lubricants). Inparticular, the lubricating oils of this disclosure can be useful forreducing wear in high soot content lubricants and diesel oils.

The lubricating oils of this disclosure provide excellent engineprotection including antiwear performance. This benefit has beendemonstrated for the lubricating oils of this disclosure in the SequenceIIIG engine tests. The low viscosity lubricating oils of this disclosureprovide improved fuel efficiency.

The lubricating engine oils of this disclosure have a compositionsufficient to pass wear protection requirements of one or more enginetests selected from Sequence IIIG and others.

The present disclosure provides lubricant compositions with excellentantiwear properties. Antiwear additives are generally required forreducing wear in operating equipment where two solid surfaces engage incontact. In the absence of antiwear chemistry, the surfaces can rubtogether causing material loss on one or both surfaces which caneventually lead to equipment malfunction and failure. Antiwear additivescan produce a protective surface layer which reduces wear and materialloss. Most commonly the materials of interest are metals such as steel.However, other material such as ceramics, polymer coatings, diamond-likecarbon, and the like can also be used to produce durable surfaces inmodern equipment. The lubricant compositions of this disclosure canprovide antiwear properties to such surfaces.

As used herein, an inorganic acid refers to a sulfonic acid, aphosphoric acid, a phosphonic acid, and other heteroatom-containingacids. Also, as used herein, inorganic acid refers tohydrocarbon-containing derivatives of the inorganic acids.

The lubricant compositions of this disclosure provide advantaged wear,including advantaged wear and friction, performance in the lubricationof internal combustion engines, power trains, drivelines, transmissions,gears, gear trains, gear sets, compressors, pumps, hydraulic systems,bearings, bushings, turbines, and the like.

Also, the lubricant compositions of this disclosure provide advantagedwear, including advantaged wear and friction, performance in thelubrication of mechanical components, which can include, for example,pistons, piston rings, cylinder liners, cylinders, cams, tappets,lifters, bearings (journal, roller, tapered, needle, ball, and thelike), gears, valves, and the like.

Further, the lubricant compositions of this disclosure provideadvantaged wear, including advantaged wear and friction, performance asa component in lubricant compositions, which can include, for example,lubricating liquids, semi-solids, solids, greases, dispersions,suspensions, material concentrates, additive concentrates, and the like.

The lubricant compositions of this disclosure are useful in additiveconcentrates that include the combination of the minor component of thisdisclosure with at least one other additive component, having combinedweight % concentrations in the range of 1% to 80%, preferably 2% to 60%,more preferably 3% to 50%, even more preferably 4% to 40%, and in someinstances preferably 5% to 30%.

Yet further, the lubricant compositions of this disclosure provideadvantaged wear, including advantaged wear and friction, performanceunder diverse lubrication regimes, that include, for example,hydrodynamic, elastohydrodynamic, boundary, mixed lubrication, extremepressure regimes, and the like.

The lubricant compositions of this disclosure provide advantaged wear,including advantaged wear and friction, performance under a range oflubrication contact pressures, from 1 MPas to greater than 10 GPas,preferably greater than 10 MPas, more preferably greater that 100 MPas,even more preferably greater than 300 MPas. Under certain circumstances,the lubricant compositions of this disclosure provide advantaged wear,including advantaged wear and friction, performance at greater than 0.5GPas, often at greater than 1 GPas, sometimes greater than 2 GPas, underselected circumstances greater than 5 GPas.

Also, the lubricant compositions of this disclosure provide advantagedwear, including advantaged wear and friction, performance inspark-ignition internal combustion engines, compression-ignitioninternal combustion engines, mixed-ignition (spark-assisted andcompression) internal combustion engines, jet- or plasma-ignitioninternal combustion engines, and the like.

Further, the lubricant compositions of this disclosure provideadvantaged wear, including advantaged wear and friction, performance indiverse engine types, which can include, for example, the following:2-stroke engines; 4-stroke engine; engines with alternate stroke designsgreater than 2-stroke, such as 5-stroke, or 7-stroke, and the like;rotary engines; dedicated EGR (exhaust gas recirculation) fueledengines; free-piston engine; engines that function in hybrid propulsionsystems, that can further include electrical-based power systems,hydraulic-based power systems, diverse system designs such as parallel,series, non-parallel, and the like.

Yet further, the lubricant compositions of this disclosure provideadvantaged wear, including advantaged wear and friction, performance in,for example, the following: naturally aspirated engines; turbochargedand supercharged, port-fueled injection engines; turbocharged andsupercharged, direct injection engines (for gasoline, diesel, naturalgas, and other fuel types); turbocharged engines designed to operatewith in-cylinder combustion pressures of greater than 12 bar, preferablygreater than 18 bar, more preferably greater than 20 bar, even morepreferably greater than 22 bar, and in certain instances combustionpressures greater than 24 bar, even greater than 26 bar, and even moreso greater than 28 bar, and with particular designs greater than 30 bar;engines having low-temperature burn combustion, lean-burn combustion,and high thermal efficiency designs.

Also, the lubricant compositions of this disclosure provide advantagedwear, including advantaged wear and friction, performance in enginesthat are fueled with fuel compositions that include, for example, thefollowing: gasoline; distillate fuel, diesel fuel, jet fuel,gas-to-liquid and Fischer-Tropsch-derived high-cetane fuels; compressednatural gas, liquefied natural gas, methane, ethane, propane, othernatural gas components, other natural gas liquids; ethanol, methanol,other higher MW alcohols; FAMEs, vegetable-derived esters andpolyesters; biodiesel, bio-derived and bio-based fuels; hydrogen;dimethyl ether; other alternate fuels; fuels diluted with EGR (exhaustgas recirculation) gases, with EGR gases enriched in hydrogen or carbonmonoxide or combinations of H₂/CO, in both dilute and high concentration(in concentrations of >0.1%, preferably >0.5%, more preferably >1%, evenmore preferably >2%, and even more so preferably >3%), and blends orcombinations of these in proportions that enhance combustion efficiency,power, cleanliness, anti-knock, and anti-LSPI (low speed pre-ignition).

Further, the lubricant compositions of this disclosure provideadvantaged wear, including advantaged wear and friction, performance onlubricated surfaces that include, for example, the following: metals,metal alloys, non-metals, non-metal alloys, mixed carbon-metalcomposites and alloys, mixed carbon-nonmetal composites and alloys,ferrous metals, ferrous composites and alloys, non-ferrous metals,non-ferrous composites and alloys, titanium, titanium composites andalloys, aluminum, aluminum composites and alloys, magnesium, magnesiumcomposites and alloys, ion-implanted metals and alloys, plasma modifiedsurfaces; surface modified materials; coatings; mono-layer, multi-layer,and gradient layered coatings; honed surfaces; polished surfaces; etchedsurfaces; textured surfaces; mircro and nano structures on texturedsurfaces; super-finished surfaces; diamond-like carbon (DLC), DLC withhigh-hydrogen content, DLC with moderate hydrogen content, DLC withlow-hydrogen content, DLC with near-zero hydrogen content, DLCcomposites, DLC-metal compositions and composites, DLC-nonmetalcompositions and composites; ceramics, ceramic oxides, ceramic nitrides,FeN, CrN, ceramic carbides, mixed ceramic compositions, and the like;polymers, thermoplastic polymers, engineered polymers, polymer blends,polymer alloys, polymer composites; materials compositions andcomposites containing dry lubricants, that include, for example,graphite, carbon, molybdenum, molybdenum disulfide,polytetrafluoroethylene, polyperfluoropropylene,polyperfluoroalkylethers, and the like.

Yet further, the lubricant compositions of this disclosure provideadvantaged wear, including advantaged wear and friction, performance onlubricated surfaces of 3-D printed materials, with or withoutpost-printing surface finishing; surfaces of 3-D printed materials thathave been post-printing treated with coatings, which may include plasmaspray coatings, ion beam-generated coatings, electrolytically- orgalvanically-generated coatings, electro-deposition coatings,vapor-deposition coatings, liquid-deposition coatings, thermal coatings,laser-based coatings; surfaces of 3-D printed materials, where thesurfaces may be as-printed, finished, or coated, that include: metals,metal alloys, non-metals, non-metal alloys, mixed carbon-metalcomposites and alloys, mixed carbon-nonmetal composites and alloys,ferrous metals, ferrous composites and alloys, non-ferrous metals,non-ferrous composites and alloys, titanium, titanium composites andalloys, aluminum, aluminum composites and alloys, magnesium, magnesiumcomposites and alloys, ion-implanted metals and alloys; plasma modifiedsurfaces; surface modified materials; mono-layer, multi-layer, andgradient layered coatings; honed surfaces; polished surfaces; etchedsurfaces; textured surfaces; mircro and nano structures on texturedsurfaces; super-finished surfaces; diamond-like carbon (DLC), DLC withhigh-hydrogen content, DLC with moderate hydrogen content, DLC withlow-hydrogen content, DLC with near-zero hydrogen content, DLCcomposites, DLC-metal compositions and composites, DLC-nonmetalcompositions and composites; ceramics, ceramic oxides, ceramic nitrides,FeN, CrN, ceramic carbides, mixed ceramic compositions, and the like;polymers, thermoplastic polymers, engineered polymers, polymer blends,polymer alloys, polymer composites; materials compositions andcomposites containing dry lubricants, that include, for example,graphite, carbon, molybdenum, molybdenum disulfide,polytetrafluoroethylene, polyperfluoropropylene,polyperfluoroalkylethers, and the like.

Still further, the lubricant compositions of this disclosure provideadvantaged synergistic wear, including advantaged synergistic wear andfriction, performance in combination with one or more performanceadditives, with performance additives at effective concentration ranges,and with performance additives at effective ratios with the minorcomponent of this disclosure.

Lubricating Oil Base Stocks

A wide range of lubricating base oils is known in the art. Lubricatingbase oils that are useful in the present disclosure are natural oils,mineral oils and synthetic oils, and unconventional oils (or mixturesthereof) can be used unrefined, refined, or rerefined (the latter isalso known as reclaimed or reprocessed oil). Unrefined oils are thoseobtained directly from a natural or synthetic source and used withoutadded purification. These include shale oil obtained directly fromretorting operations, petroleum oil obtained directly from primarydistillation, and ester oil obtained directly from an esterificationprocess. Refined oils are similar to the oils discussed for unrefinedoils except refined oils are subjected to one or more purification stepsto improve at least one lubricating oil property. One skilled in the artis familiar with many purification processes. These processes includesolvent extraction, secondary distillation, acid extraction, baseextraction, filtration, and percolation. Rerefined oils are obtained byprocesses analogous to refined oils but using an oil that has beenpreviously used as a feed stock.

Groups I, II, III, IV and V are broad base oil stock categoriesdeveloped and defined by the American Petroleum Institute (APIPublication 1509; www.API.org) to create guidelines for lubricant baseoils. Group I base stocks have a viscosity index of between about 80 to120 and contain greater than about 0.03% sulfur and/or less than about90% saturates. Group II base stocks have a viscosity index of betweenabout 80 to 120, and contain less than or equal to about 0.03% sulfurand greater than or equal to about 90% saturates. Group III stocks havea viscosity index greater than about 120 and contain less than or equalto about 0.03% sulfur and greater than about 90% saturates. Group IVincludes polyalphaolefins (PAO). Group V base stock includes base stocksnot included in Groups I-IV. The table below summarizes properties ofeach of these five groups.

Base Oil Properties Saturates Sulfur Viscosity Index Group I   <90and/or  >0.03% and ≥80 and <120 Group II ≥90 and ≤0.03% and ≥80 and <120Group III ≥90 and ≤0.03% and ≥120 Group IV polyalphaolefins (PAO) GroupV All other base oil stocks not included in Groups I, II, III or IV

Natural oils include animal oils, vegetable oils (castor oil and lardoil, for example), and mineral oils. Animal and vegetable oilspossessing favorable thermal oxidative stability can be used. Of thenatural oils, mineral oils are preferred. Mineral oils vary widely as totheir crude source, for example, as to whether they are paraffinic,naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal orshale are also useful. Natural oils vary also as to the method used fortheir production and purification, for example, their distillation rangeand whether they are straight run or cracked, hydrorefined, or solventextracted.

Group II and/or Group III hydroprocessed or hydrocracked base stocks,including synthetic oils such as alkyl aromatics and synthetic estersare also well known base stock oils.

Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oilssuch as polymerized and interpolymerized olefins (polybutylenes,polypropylenes, propylene isobutylene copolymers, ethylene-olefincopolymers, and ethylene-alphaolefin copolymers, for example).Polyalphaolefin (PAO) oil base stocks are commonly used synthetichydrocarbon oil. By way of example, PAOs derived from C₈, C₁₀, C₁₂, C₁₄olefins or mixtures thereof may be utilized. See U.S. Pat. Nos.4,956,122; 4,827,064; and 4,827,073.

The number average molecular weights of the PAOs, which are knownmaterials and generally available on a major commercial scale fromsuppliers such as ExxonMobil Chemical Company, Chevron Phillips ChemicalCompany, BP, and others, typically vary from about 250 to about 3,000,although PAO's may be made in viscosities up to about 150 cSt (100° C.).The PAOs are typically comprised of relatively low molecular weighthydrogenated polymers or oligomers of alphaolefins which include, butare not limited to, C₂ to about C₃₂ alphaolefins with the C₈ to aboutC₁₆ alphaolefins, such as 1-octene, 1-decene, 1-dodecene and the like,being preferred. The preferred polyalphaolefins are poly-1-octene,poly-1-decene and poly-1-dodecene and mixtures thereof and mixedolefin-derived polyolefins. However, the dimers of higher olefins in therange of C₁₄ to Cis may be used to provide low viscosity base stocks ofacceptably low volatility. Depending on the viscosity grade and thestarting oligomer, the PAOs may be predominantly trimers and tetramersof the starting olefins, with minor amounts of the higher oligomers,having a viscosity range of 1.5 to 12 cSt. PAO fluids of particular usemay include 3.0 cSt, 3.4 cSt, and/or 3.6 cSt and combinations thereof.Mixtures of PAO fluids having a viscosity range of 1.5 to approximately150 cSt or more may be used if desired.

The PAO fluids may be conveniently made by the polymerization of analphaolefin in the presence of a polymerization catalyst such as theFriedel-Crafts catalysts including, for example, aluminum trichloride,boron trifluoride or complexes of boron trifluoride with water, alcoholssuch as ethanol, propanol or butanol, carboxylic acids or esters such asethyl acetate or ethyl propionate. For example the methods disclosed byU.S. Pat. No. 4,149,178 or 3,382,291 may be conveniently used herein.Other descriptions of PAO synthesis are found in the following U.S. Pat.Nos. 3,742,082; 3,769,363; 3,876,720; 4,239,930; 4,367,352; 4,413,156;4,434,408; 4,910,355; 4,956,122; and 5,068,487. The dimers of the C₁₄ toC₁₈ olefins are described in U.S. Pat. No. 4,218,330.

Other useful lubricant oil base stocks include wax isomerate base stocksand base oils, comprising hydroisomerized waxy stocks (e.g. waxy stockssuch as gas oils, slack waxes, fuels hydrocracker bottoms, etc.),hydroisomerized Fischer-Tropsch waxes, Gas-to-Liquids (GTL) base stocksand base oils, and other wax isomerate hydroisomerized base stocks andbase oils, or mixtures thereof. Fischer-Tropsch waxes, the high boilingpoint residues of Fischer-Tropsch synthesis, are highly paraffinichydrocarbons with very low sulfur content. The hydroprocessing used forthe production of such base stocks may use an amorphoushydrocracking/hydroisomerization catalyst, such as one of thespecialized lube hydrocracking (LHDC) catalysts or a crystallinehydrocracking/hydroisomerization catalyst, preferably a zeoliticcatalyst. For example, one useful catalyst is ZSM-48 as described inU.S. Pat. No. 5,075,269, the disclosure of which is incorporated hereinby reference in its entirety. Processes for making hydrocracked/hydroisomerized distillates and hydrocracked/hydroisomerized waxes aredescribed, for example, in U.S. Pat. Nos. 2,817,693; 4,975,177;4,921,594 and 4,897,178 as well as in British Patent Nos. 1,429,494;1,350,257; 1,440,230 and 1,390,359. Each of the aforementioned patentsis incorporated herein in their entirety. Particularly favorableprocesses are described in European Patent Application Nos. 464546 and464547, also incorporated herein by reference. Processes usingFischer-Tropsch wax feeds are described in U.S. Pat. Nos. 4,594,172 and4,943,672, the disclosures of which are incorporated herein by referencein their entirety.

Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils,and other wax-derived hydroisomerized (wax isomerate) base oils beadvantageously used in the instant disclosure, and may have usefulkinematic viscosities at 100° C. of about 3 cSt to about 50 cSt,preferably about 3 cSt to about 30 cSt, more preferably about 3.5 cSt toabout 25 cSt, as exemplified by GTL 4 with kinematic viscosity of about4.0 cSt at 100° C. and a viscosity index of about 141. TheseGas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils,and other wax-derived hydroisomerized base oils may have useful pourpoints of about −20° C. or lower, and under some conditions may haveadvantageous pour points of about −25° C. or lower, with useful pourpoints of about −30° C. to about −40° C. or lower. Useful compositionsof Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived baseoils, and wax-derived hydroisomerized base oils are recited in U.S. Pat.Nos. 6,080,301; 6,090,989, and 6,165,949 for example, and areincorporated herein in their entirety by reference.

The hydrocarbyl aromatics can be used as a base oil or base oilcomponent and can be any hydrocarbyl molecule that contains at leastabout 5% of its weight derived from an aromatic moiety such as abenzenoid moiety or naphthenoid moiety, or their derivatives. Thesehydrocarbyl aromatics include alkyl benzenes, alkyl naphthalenes, alkyldiphenyl oxides, alkyl naphthols, alkyl diphenyl sulfides, alkylatedbis-phenol A, alkylated thiodiphenol, and the like. The aromatic can bemono-alkylated, dialkylated, polyalkylated, and the like. The aromaticcan be mono- or poly-functionalized. The hydrocarbyl groups can also becomprised of mixtures of alkyl groups, alkenyl groups, alkynyl,cycloalkyl groups, cycloalkenyl groups and other related hydrocarbylgroups. The hydrocarbyl groups can range from about C₆ up to about C₆₀with a range of about C₈ to about C₂₀ often being preferred. A mixtureof hydrocarbyl groups is often preferred, and up to about three suchsubstituents may be present. The hydrocarbyl group can optionallycontain sulfur, oxygen, and/or nitrogen containing substituents. Thearomatic group can also be derived from natural (petroleum) sources,provided at least about 5% of the molecule is comprised of an above-typearomatic moiety. Viscosities at 100° C. of approximately 3 cSt to about50 cSt are preferred, with viscosities of approximately 3.4 cSt to about20 cSt often being more preferred for the hydrocarbyl aromaticcomponent. In one embodiment, an alkyl naphthalene where the alkyl groupis primarily comprised of 1-hexadecene is used. Other alkylates ofaromatics can be advantageously used. Naphthalene or methyl naphthalene,for example, can be alkylated with olefins such as octene, decene,dodecene, tetradecene or higher, mixtures of similar olefins, and thelike. Useful concentrations of hydrocarbyl aromatic in a lubricant oilcomposition can be about 2% to about 25%, preferably about 4% to about20%, and more preferably about 4% to about 15%, depending on theapplication.

Alkylated aromatics such as the hydrocarbyl aromatics of the presentdisclosure may be produced by well-known Friedel-Crafts alkylation ofaromatic compounds. See Friedel-Crafts and Related Reactions, Olah, G.A. (ed.), Inter-science Publishers, New York, 1963. For example, anaromatic compound, such as benzene or naphthalene, is alkylated by anolefin, alkyl halide or alcohol in the presence of a Friedel-Craftscatalyst. See Friedel-Crafts and Related Reactions, Vol. 2, part 1,chapters 14, 17, and 18, See Olah, G. A. (ed.), Inter-sciencePublishers, New York, 1964. Many homogeneous or heterogeneous, solidcatalysts are known to one skilled in the art. The choice of catalystdepends on the reactivity of the starting materials and product qualityrequirements. For example, strong acids such as AlCl₃, BF₃, or HF may beused. In some cases, milder catalysts such as FeCl₃ or SnCl₄ arepreferred. Newer alkylation technology uses zeolites or solid superacids.

Esters comprise a useful base stock. Additive solvency and sealcompatibility characteristics may be secured by the use of esters suchas the esters of dibasic acids with monoalkanols and the polyol estersof monocarboxylic acids. Esters of the former type include, for example,the esters of dicarboxylic acids such as phthalic acid, succinic acid,alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid,suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic aciddimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, etc.,with a variety of alcohols such as butyl alcohol, hexyl alcohol, dodecylalcohol, 2-ethylhexyl alcohol, etc. Specific examples of these types ofesters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexylfumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, etc.

Particularly useful synthetic esters are those which are obtained byreacting one or more polyhydric alcohols, preferably the hinderedpolyols (such as the neopentyl polyols, e.g., neopentyl glycol,trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylolpropane, pentaerythritol and dipentaerythritol) with alkanoic acidscontaining at least about 4 carbon atoms, preferably C₅ to C₃₀ acidssuch as saturated straight chain fatty acids including caprylic acid,capric acid, lauric acid, myristic acid, palmitic acid, stearic acid,arachic acid, and behenic acid, or the corresponding branched chainfatty acids or unsaturated fatty acids such as oleic acid, or mixturesof any of these materials.

Suitable synthetic ester components include the esters of trimethylolpropane, trimethylol butane, trimethylol ethane, pentaerythritol and/ordipentaerythritol with one or more monocarboxylic acids containing fromabout 5 to about 10 carbon atoms. These esters are widely availablecommercially, for example, the Mobil P-41 and P-51 esters of ExxonMobilChemical Company.

Also useful are esters derived from renewable material such as coconut,palm, rapeseed, soy, sunflower and the like. These esters may bemonoesters, di-esters, polyol esters, complex esters, or mixturesthereof. These esters are widely available commercially, for example,the Esterex NP 343 ester of ExxonMobil Chemical Company.

Engine oil formulations containing renewable esters are included in thisdisclosure. For such formulations, the renewable content of the ester istypically greater than about 70 weight percent, preferably more thanabout 80 weight percent and most preferably more than about 90 weightpercent.

Other useful fluids of lubricating viscosity include non-conventional orunconventional base stocks that have been processed, preferablycatalytically, or synthesized to provide high performance lubricationcharacteristics.

Non-conventional or unconventional base stocks/base oils include one ormore of a mixture of base stock(s) derived from one or moreGas-to-Liquids (GTL) materials, as well as isomerate/isodewaxate basestock(s) derived from natural wax or waxy feeds, mineral and ornon-mineral oil waxy feed stocks such as slack waxes, natural waxes, andwaxy stocks such as gas oils, waxy fuels hydrocracker bottoms, waxyraffinate, hydrocrackate, thermal crackates, or other mineral, mineraloil, or even non-petroleum oil derived waxy materials such as waxymaterials received from coal liquefaction or shale oil, and mixtures ofsuch base stocks.

GTL materials are materials that are derived via one or more synthesis,combination, transformation, rearrangement, and/ordegradation/deconstructive processes from gaseous carbon-containingcompounds, hydrogen-containing compounds and/or elements as feed stockssuch as hydrogen, carbon dioxide, carbon monoxide, water, methane,ethane, ethylene, acetylene, propane, propylene, propyne, butane,butylenes, and butynes. GTL base stocks and/or base oils are GTLmaterials of lubricating viscosity that are generally derived fromhydrocarbons; for example, waxy synthesized hydrocarbons, that arethemselves derived from simpler gaseous carbon-containing compounds,hydrogen-containing compounds and/or elements as feed stocks. GTL basestock(s) and/or base oil(s) include oils boiling in the lube oil boilingrange (1) separated/fractionated from synthesized GTL materials such as,for example, by distillation and subsequently subjected to a final waxprocessing step which involves either or both of a catalytic dewaxingprocess, or a solvent dewaxing process, to produce lube oils ofreduced/low pour point; (2) synthesized wax isomerates, comprising, forexample, hydrodewaxed or hydroisomerized cat and/or solvent dewaxedsynthesized wax or waxy hydrocarbons; (3) hydrodewaxed orhydroisomerized cat and/or solvent dewaxed Fischer-Tropsch (F-T)material (i.e., hydrocarbons, waxy hydrocarbons, waxes and possibleanalogous oxygenates); preferably hydrodewaxed orhydroisomerized/followed by cat and/or solvent dewaxing dewaxed F-T waxyhydrocarbons, or hydrodewaxed or hydroisomerized/followed by cat (orsolvent) dewaxing dewaxed, F-T waxes, or mixtures thereof.

GTL base stock(s) and/or base oil(s) derived from GTL materials,especially, hydrodewaxed or hydroisomerized/followed by cat and/orsolvent dewaxed wax or waxy feed, preferably F-T material derived basestock(s) and/or base oil(s), are characterized typically as havingkinematic viscosities at 100° C. of from about 2 mm²/s to about 50 mm²/s(ASTM D445). They are further characterized typically as having pourpoints of −5° C. to about −40° C. or lower (ASTM D97). They are alsocharacterized typically as having viscosity indices of about 80 to about140 or greater (ASTM D2270).

In addition, the GTL base stock(s) and/or base oil(s) are typicallyhighly paraffinic (>90% saturates), and may contain mixtures ofmonocycloparaffins and multicycloparaffins in combination withnon-cyclic isoparaffins. The ratio of the naphthenic (i.e.,cycloparaffin) content in such combinations varies with the catalyst andtemperature used. Further, GTL base stock(s) and/or base oil(s)typically have very low sulfur and nitrogen content, generallycontaining less than about 10 ppm, and more typically less than about 5ppm of each of these elements. The sulfur and nitrogen content of GTLbase stock(s) and/or base oil(s) obtained from F-T material, especiallyF-T wax, is essentially nil. In addition, the absence of phosphorus andaromatics make this materially especially suitable for the formulationof low SAP products.

The term GTL base stock and/or base oil and/or wax isomerate base stockand/or base oil is to be understood as embracing individual fractions ofsuch materials of wide viscosity range as recovered in the productionprocess, mixtures of two or more of such fractions, as well as mixturesof one or two or more low viscosity fractions with one, two or morehigher viscosity fractions to produce a blend wherein the blend exhibitsa target kinematic viscosity.

The GTL material, from which the GTL base stock(s) and/or base oil(s)is/are derived is preferably an F-T material (i.e., hydrocarbons, waxyhydrocarbons, wax).

Base oils for use in the formulated lubricating oils useful in thepresent disclosure are any of the variety of oils corresponding to APIGroup I, Group II, Group III, Group IV, and Group V oils and mixturesthereof, preferably API Group II, Group III, Group IV, and Group V oilsand mixtures thereof, more preferably the Group III to Group V base oilsdue to their exceptional volatility, stability, viscometric andcleanliness features. Minor quantities of Group I stock, such as theamount used to dilute additives for blending into formulated lube oilproducts, can be tolerated but should be kept to a minimum, i.e. amountsonly associated with their use as diluent/carrier oil for additives usedon an “as-received” basis. Even in regard to the Group II stocks, it ispreferred that the Group II stock be in the higher quality rangeassociated with that stock, i.e. a Group II stock having a viscosityindex in the range 100<VI<120.

The base oil constitutes the major component of the engine oil lubricantcomposition of the present disclosure and typically is present in anamount ranging from about 50 to about 99 weight percent, preferably fromabout 70 to about 95 weight percent, and more preferably from about 85to about 95 weight percent, based on the total weight of thecomposition. The base oil may be selected from any of the synthetic ornatural oils typically used as crankcase lubricating oils forspark-ignited and compression-ignited engines. The base oil convenientlyhas a kinematic viscosity, according to ASTM standards, of about 2.5 cStto about 12 cSt (or mm²/s) at 100° C. and preferably of about 2.5 cSt toabout 9 cSt (or mm²/s) at 100° C. Mixtures of synthetic and natural baseoils may be used if desired. Bi-modal mixtures of Group I, II, III, IV,and/or V base stocks may be used if desired.

Antiwear Additive

Illustrative antiwear additives useful in this disclosure include, forexample, metal salts of a carboxylic acid. The metal is selected from atransition metal and mixtures thereof. The carboxylic acid is selectedfrom an aliphatic carboxylic acid, a cycloaliphatic carboxylic acid, anaromatic carboxylic acid, and mixtures thereof.

The metal is preferably selected from a Group 10, 11 and 12 metal, andmixtures thereof. The carboxylic acid is preferably an aliphatic,saturated, unbranched carboxylic acid having from about 8 to about 26carbon atoms, and mixtures thereof.

The metal is preferably selected from nickel (Ni), palladium (Pd),platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), andmixtures thereof.

The carboxylic acid is preferably selected from caprylic acid (C8),pelargonic acid (C9), capric acid (C10), undecylic acid (C11), lauricacid (C12), tridecylic acid (C13), myristic acid (C14), pentadecylicacid (C15), palmitic acid (C16), margaric acid (C17), isostearic acid(C18), stearic acid (C18), nonadecylic acid (C19), arachidic acid (C20),heneicosylic acid (C21), behenic acid (C22), tricosylic acid (C23),lignoceric acid (C24), pentacosylic acid (C25), cerotic acid (C26), andmixtures thereof.

Preferably, the metal salt of a carboxylic acid comprises zinc stearate,silver stearate, palladium stearate, zinc palmitate, silver palmitate,palladium palmitate, and mixtures thereof.

The metal salt of a carboxylic acid is present in the engine oilformulations of this disclosure in an amount of from about 0.01 weightpercent to about 5 weight percent, based on the total weight of theformulated oil.

Low phosphorus engine oil formulations are included in this disclosure.For such formulations, the phosphorus content is typically less thanabout 0.12 weight percent, preferably less than about 0.10 weightpercent, more preferably less than about 0.085 weight percent, and mostpreferably less than about 0.04 weight percent.

Detergents

Illustrative detergents useful in this disclosure include, for example,alkali metal detergents, alkaline earth metal detergents, or mixtures ofone or more alkali metal detergents and one or more alkaline earth metaldetergents. A typical detergent is an anionic material that contains along chain hydrophobic portion of the molecule and a smaller anionic oroleophobic hydrophilic portion of the molecule. The anionic portion ofthe detergent is typically derived from an organic acid such as asulfur-containing acid, carboxylic acid (e.g., salicylic acid),phosphorus-containing acid, phenol, or mixtures thereof. The counterionis typically an alkaline earth or alkali metal. The detergent can beoverbased as described herein.

The detergent is preferably a metal salt of an organic or inorganicacid, a metal salt of a phenol, or mixtures thereof. The metal ispreferably selected from an alkali metal, an alkaline earth metal, andmixtures thereof. The organic or inorganic acid is selected from analiphatic organic or inorganic acid, a cycloaliphatic organic orinorganic acid, an aromatic organic or inorganic acid, and mixturesthereof.

The metal is preferably selected from an alkali metal, an alkaline earthmetal, and mixtures thereof. More preferably, the metal is selected fromcalcium (Ca), magnesium (Mg), and mixtures thereof.

The organic acid or inorganic acid is preferably selected from asulfur-containing acid, a carboxylic acid, a phosphorus-containing acid,and mixtures thereof.

Preferably, the metal salt of an organic or inorganic acid or the metalsalt of a phenol comprises calcium phenate, calcium sulfonate, calciumsalicylate, magnesium phenate, magnesium sulfonate, magnesiumsalicylate, an overbased detergent, and mixtures thereof. Preferably themetal salt of the organic acid or the inorganic acid or the phenol isoverbased. Most preferably the salts are overbased with carbonate.

Salts that contain a substantially stochiometric amount of the metal aredescribed as neutral salts and have a total base number (TBN, asmeasured by ASTM D2896) of from 0 to 80. Many compositions areoverbased, containing large amounts of a metal base that is achieved byreacting an excess of a metal compound (a metal hydroxide or oxide, forexample) with an acidic gas (such as carbon dioxide). Useful detergentscan be neutral, mildly overbased, or highly overbased. These detergentscan be used in mixtures of neutral, overbased, highly overbased calciumsalicylate, sulfonates, phenates and/or magnesium salicylate,sulfonates, phenates. The TBN ranges can vary from low, medium to highTBN products, including as low as 0 to as high as 600, or 50 to 500, or100 to 400, or 200 to 400. Preferably the TBN delivered by the detergentis between 1 and 20. More preferably between 1 and 12. Mixtures of low,medium, high TBN can be used, along with mixtures of calcium andmagnesium metal based detergents, and including sulfonates, phenates,salicylates, and carboxylates. A detergent mixture with a metal ratio of1, in conjunction of a detergent with a metal ratio of 2, and as high asa detergent with a metal ratio of 5, can be used. Borated detergents canalso be used.

Alkaline earth phenates are another useful class of detergent. Thesedetergents can be made by reacting alkaline earth metal hydroxide oroxide (CaO, Ca(OH)₂, BaO, Ba(OH)₂, MgO, Mg(OH)₂, for example) with analkyl phenol or sulfurized alkylphenol. Useful alkyl groups 15 includestraight chain or branched C₁-C₃₀ alkyl groups, preferably, C₄-C₂₀ ormixtures thereof. Examples of suitable phenols include isobutylphenol,2-ethylhexylphenol, nonylphenol, dodecyl phenol, and the like. It shouldbe noted that starting alkylphenols may contain more than one alkylsubstituent that are each independently straight chain or branched andcan be used from 0.5 to 6 weight percent. When a non-sulfurizedalkylphenol is used, the sulfurized product may be obtained by methodswell known in the art. These methods include heating a mixture ofalkylphenol and sulfurizing agent (including elemental sulfur, sulfurhalides such as sulfur dichloride, and the like) and then reacting thesulfurized phenol with an alkaline earth metal base.

In accordance with this disclosure, metal salts of carboxylic acids arepreferred detergents. These carboxylic acid detergents may be preparedby reacting a basic metal compound with at least one carboxylic acid andremoving free water from the reaction product. These compounds may beoverbased to produce the desired TBN level. Detergents made fromsalicylic acid are one preferred class of detergents derived fromcarboxylic acids. Useful salicylates include long chain alkylsalicylates. One useful family of compositions is of the formula

where R is an alkyl group having 1 to about 30 carbon atoms, n is aninteger from 1 to 4, and M is an alkaline earth metal. Preferred Rgroups are alkyl chains of at least C₁₁, preferably C₁₃ or greater. Rmay be optionally substituted with substituents that do not interferewith the detergent's function. M is preferably, calcium, magnesium, orbarium. More preferably, M is calcium.

Hydrocarbyl-substituted salicylic acids may be prepared from phenols bythe Kolbe reaction (see U.S. Pat. No. 3,595,791). The metal salts of thehydrocarbyl-substituted salicylic acids may be prepared by doubledecomposition of a metal salt in a polar solvent such as water oralcohol.

Alkaline earth metal phosphates are also used as detergents and areknown in the art.

Detergents may be simple detergents or what is known as hybrid orcomplex detergents. The latter detergents can provide the properties oftwo detergents without the need to blend separate materials. See U.S.Pat. No. 6,034,039.

Preferred detergents include calcium sulfonates, magnesium sulfonates,calcium salicylates, magnesium salicylates, calcium phenates, magnesiumphenates, and other related components (including borated detergents),and mixtures thereof. Preferred mixtures of detergents include magnesiumsulfonate and calcium salicylate, magnesium sulfonate and calciumsulfonate, magnesium sulfonate and calcium phenate, calcium phenate andcalcium salicylate, calcium phenate and calcium sulfonate, calciumphenate and magnesium salicylate, calcium phenate and magnesium phenate.Overbased detergents are also preferred.

The detergent concentration in the lubricating oils of this disclosurecan range from about 0.5 to about 6.0 weight percent, preferably about0.6 to 5.0 weight percent, and more preferably from about 0.8 weightpercent to about 4.0 weight percent, based on the total weight of thelubricating oil.

As used herein, the detergent concentrations are given on an “asdelivered” basis. Typically, the active detergent is delivered with aprocess oil. The “as delivered” detergent typically contains from about20 weight percent to about 100 weight percent, or from about 40 weightpercent to about 60 weight percent, of active detergent in the “asdelivered” detergent product.

Other Additives

The formulated lubricating oil useful in the present disclosure mayadditionally contain one or more of the other commonly used lubricatingoil performance additives including but not limited to other antiwearadditives, dispersants, viscosity modifiers, corrosion inhibitors, rustinhibitors, metal deactivators, extreme pressure additives, anti-seizureagents, wax modifiers, other viscosity modifiers, fluid-loss additives,seal compatibility agents, lubricity agents, anti-staining agents,chromophoric agents, defoamants, demulsifiers, emulsifiers, densifiers,wetting agents, gelling agents, tackiness agents, colorants, and others.For a review of many commonly used additives, see Klamann in Lubricantsand Related Products, Verlag Chemie, Deerfield Beach, Fla.; ISBN0-89573-177-0. Reference is also made to “Lubricant Additives” by M. W.Ranney, published by Noyes Data Corporation of Parkridge, N J (1973);see also U.S. Pat. No. 7,704,930, the disclosure of which isincorporated herein in its entirety. These additives are commonlydelivered with varying amounts of diluent oil, that may range from 5weight percent to 50 weight percent.

The additives useful in this disclosure do not have to be soluble in thelubricating oils. Insoluble additives such as zinc stearate in oil canbe dispersed in the lubricating oils of this disclosure.

The types and quantities of performance additives used in combinationwith the instant disclosure in lubricant compositions are not limited bythe examples shown herein as illustrations.

Other Antiwear Additives

A metal alkylthiophosphate and more particularly a metal dialkyl dithiophosphate in which the metal constituent is zinc, or zinc dialkyl dithiophosphate (ZDDP) can be a useful component of the lubricating oils ofthis disclosure. ZDDP can be derived from primary alcohols, secondaryalcohols or mixtures thereof. ZDDP compounds generally are of theformula

Zn[SP(S)(OR¹)(OR²)]₂

where R¹ and R² are C₁-C₁₈ alkyl groups, preferably C₂-C₁₂ alkyl groups.These alkyl groups may be straight chain or branched. Alcohols used inthe ZDDP can be 2-propanol, butanol, secondary butanol, pentanols,hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethylhexanol, alkylated phenols, and the like. Mixtures of secondary alcoholsor of primary and secondary alcohol can be preferred. Alkyl aryl groupsmay also be used.

Preferable zinc dithiophosphates which are commercially availableinclude secondary zinc dithiophosphates such as those available from forexample, The Lubrizol Corporation under the trade designations “LZ677A”, “LZ 1095” and “LZ 1371”, from for example Chevron Oronite underthe trade designation “OLOA 262” and from for example Afton Chemicalunder the trade designation “HITEC 7169”.

The ZDDP is typically used in amounts of from about 0.4 weight percentto about 1.2 weight percent, preferably from about 0.5 weight percent toabout 1.0 weight percent, and more preferably from about 0.6 weightpercent to about 0.8 weight percent, based on the total weight of thelubricating oil, although more or less can often be used advantageously.Preferably, the ZDDP is a secondary ZDDP and present in an amount offrom about 0.6 to 1.0 weight percent of the total weight of thelubricating oil.

Low phosphorus engine oil formulations are included in this disclosure.For such formulations, the phosphorus content is typically less thanabout 0.12 weight percent preferably less than about 0.10 weight percentand most preferably less than about 0.085 weight percent.

Dispersants

During engine operation, oil-insoluble oxidation byproducts areproduced. Dispersants help keep these byproducts in solution, thusdiminishing their deposition on metal surfaces. Dispersants used in theformulation of the lubricating oil may be ashless or ash-forming innature. Preferably, the dispersant is ashless. So called ashlessdispersants are organic materials that form substantially no ash uponcombustion. For example, non-metal-containing or borated metal-freedispersants are considered ashless. In contrast, metal-containingdetergents discussed above form ash upon combustion.

Suitable dispersants typically contain a polar group attached to arelatively high molecular weight hydrocarbon chain. The polar grouptypically contains at least one element of nitrogen, oxygen, orphosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.

A particularly useful class of dispersants are the (poly)alkenylsuccinicderivatives, typically produced by the reaction of a long chainhydrocarbyl substituted succinic compound, usually a hydrocarbylsubstituted succinic anhydride, with a polyhydroxy or polyaminocompound. The long chain hydrocarbyl group constituting the oleophilicportion of the molecule which confers solubility in the oil, is normallya polyisobutylene group. Many examples of this type of dispersant arewell known commercially and in the literature. Exemplary U.S. patentsdescribing such dispersants are U.S. Pat. Nos. 3,172,892; 3,2145,707;3,219,666; 3,316,177; 3,341,542; 3,444,170; 3,454,607; 3,541,012;3,630,904; 3,632,511; 3,787,374 and 4,234,435. Other types of dispersantare described in U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025;3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574;3,725,277; 3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250;3,519,565; 3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. Afurther description of dispersants may be found, for example, inEuropean Patent Application No. 471 071, to which reference is made forthis purpose.

Hydrocarbyl-substituted succinic acid and hydrocarbyl-substitutedsuccinic anhydride derivatives are useful dispersants. In particular,succinimide, succinate esters, or succinate ester amides prepared by thereaction of a hydrocarbon-substituted succinic acid compound preferablyhaving at least 50 carbon atoms in the hydrocarbon substituent, with atleast one equivalent of an alkylene amine are particularly useful.

Succinimides are formed by the condensation reaction between hydrocarbylsubstituted succinic anhydrides and amines. Molar ratios can varydepending on the polyamine. For example, the molar ratio of hydrocarbylsubstituted succinic anhydride to TEPA can vary from about 1:1 to about5:1. Representative examples are shown in U.S. Pat. Nos. 3,087,936;3,172,892; 3,219,666; 3,272,746; 3,322,670; and U.S. Pat. Nos.3,652,616, 3,948,800; and Canada Patent No. 1,094,044.

Succinate esters are formed by the condensation reaction betweenhydrocarbyl substituted succinic anhydrides and alcohols or polyols.Molar ratios can vary depending on the alcohol or polyol used. Forexample, the condensation product of a hydrocarbyl substituted succinicanhydride and pentaerythritol is a useful dispersant.

Succinate ester amides are formed by condensation reaction betweenhydrocarbyl substituted succinic anhydrides and alkanol amines. Forexample, suitable alkanol amines include ethoxylatedpolyalkylpolyamines, propoxylated polyalkylpolyamines andpolyalkenylpolyamines such as polyethylene polyamines. One example ispropoxylated hexamethylenediamine. Representative examples are shown inU.S. Pat. No. 4,426,305.

The molecular weight of the hydrocarbyl substituted succinic anhydridesused in the preceding paragraphs will typically range between 800 and2,500 or more. The above products can be post-reacted with variousreagents such as sulfur, oxygen, formaldehyde, carboxylic acids such asoleic acid. The above products can also be post reacted with boroncompounds such as boric acid, borate esters or highly borateddispersants, to form borated dispersants generally having from about 0.1to about 5 moles of boron per mole of dispersant reaction product.

Mannich base dispersants are made from the reaction of alkylphenols,formaldehyde, and amines. See U.S. Pat. No. 4,767,551, which isincorporated herein by reference. Process aids and catalysts, such asoleic acid and sulfonic acids, can also be part of the reaction mixture.Molecular weights of the alkylphenols range from 800 to 2,500.Representative examples are shown in U.S. Pat. Nos. 3,697,574;3,703,536; 3,704,308; 3,751,365; 3,756,953; 3,798,165; and 3,803,039.

Typical high molecular weight aliphatic acid modified Mannichcondensation products useful in this disclosure can be prepared fromhigh molecular weight alkyl-substituted hydroxyaromatics or HNR₂group-containing reactants.

Hydrocarbyl substituted amine ashless dispersant additives are wellknown to one skilled in the art; see, for example, U.S. Pat. Nos.3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209, and 5,084,197.

Preferred dispersants include borated and non-borated succinimides,including those derivatives from mono-succinimides, bis-succinimides,and/or mixtures of mono- and bis-succinimides, wherein the hydrocarbylsuccinimide is derived from a hydrocarbylene group such aspolyisobutylene having a Mn of from about 500 to about 5000, or fromabout 1000 to about 3000, or about 1000 to about 2000, or a mixture ofsuch hydrocarbylene groups, often with high terminal vinylic groups.Other preferred dispersants include succinic acid-esters and amides,alkylphenol-polyamine-coupled Mannich adducts, their capped derivatives,and other related components.

Polymethacrylate or polyacrylate derivatives are another class ofdispersants. These dispersants are typically prepared by reacting anitrogen containing monomer and a methacrylic or acrylic acid esterscontaining 5-25 carbon atoms in the ester group. Representative examplesare shown in U.S. Pat. Nos. 2,100,993, and 6,323,164. Polymethacrylateand polyacrylate dispersants are normally used as multifunctionalviscosity modifiers. The lower molecular weight versions can be used aslubricant dispersants or fuel detergents.

Illustrative preferred dispersants useful in this disclosure includethose derived from polyalkenyl-substituted mono- or dicarboxylic acid,anhydride or ester, which dispersant has a polyalkenyl moiety with anumber average molecular weight of at least 900 and from greater than1.3 to 1.7, preferably from greater than 1.3 to 1.6, most preferablyfrom greater than 1.3 to 1.5, functional groups (mono- or dicarboxylicacid producing moieties) per polyalkenyl moiety (a medium functionalitydispersant). Functionality (F) can be determined according to thefollowing formula:

F=(SAP×M _(n))/((112,200×A.I.)−(SAP×98))

wherein SAP is the saponification number (i.e., the number of milligramsof KOH consumed in the complete neutralization of the acid groups in onegram of the succinic-containing reaction product, as determinedaccording to ASTM D94); M_(n) is the number average molecular weight ofthe starting olefin polymer; and A.I. is the percent active ingredientof the succinic-containing reaction product (the remainder beingunreacted olefin polymer, succinic anhydride and diluent).

The polyalkenyl moiety of the dispersant may have a number averagemolecular weight of at least 900, suitably at least 1500, preferablybetween 1800 and 3000, such as between 2000 and 2800, more preferablyfrom about 2100 to 2500, and most preferably from about 2200 to about2400. The molecular weight of a dispersant is generally expressed interms of the molecular weight of the polyalkenyl moiety. This is becausethe precise molecular weight range of the dispersant depends on numerousparameters including the type of polymer used to derive the dispersant,the number of functional groups, and the type of nucleophilic groupemployed.

Polymer molecular weight, specifically M_(n), can be determined byvarious known techniques. One convenient method is gel permeationchromatography (GPC), which additionally provides molecular weightdistribution information (see W. W. Yau, J. J. Kirkland and D. D. Bly,“Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, NewYork, 1979). Another useful method for determining molecular weight,particularly for lower molecular weight polymers, is vapor pressureosmometry (e.g., ASTM D3592).

The polyalkenyl moiety in a dispersant preferably has a narrow molecularweight distribution (MWD), also referred to as polydispersity, asdetermined by the ratio of weight average molecular weight (M_(w)) tonumber average molecular weight (M_(n)). Polymers having a M_(w)/M_(n)of less than 2.2, preferably less than 2.0, are most desirable. Suitablepolymers have a polydispersity of from about 1.5 to 2.1, preferably fromabout 1.6 to about 1.8.

Suitable polyalkenes employed in the formation of the dispersantsinclude homopolymers, interpolymers or lower molecular weighthydrocarbons. One family of such polymers comprise polymers of ethyleneand/or at least one C₃ to C₂ alpha-olefin having the formula H₂C═CHR¹wherein R¹ is a straight or branched chain alkyl radical comprising 1 to26 carbon atoms and wherein the polymer contains carbon-to-carbonunsaturation, and a high degree of terminal ethenylidene unsaturation.Preferably, such polymers comprise interpolymers of ethylene and atleast one alpha-olefin of the above formula, wherein R¹ is alkyl of from1 to 18 carbon atoms, and more preferably is alkyl of from 1 to 8 carbonatoms, and more preferably still of from 1 to 2 carbon atoms.

Another useful class of polymers is polymers prepared by cationicpolymerization of monomers such as isobutene and styrene. Commonpolymers from this class include polyisobutenes obtained bypolymerization of a C₄ refinery stream having a butene content of 35 to75% by wt., and an isobutene content of 30 to 60% by wt. A preferredsource of monomer for making poly-n-butenes is petroleum feedstreamssuch as Raffinate II. These feedstocks are disclosed in the art such asin U.S. Pat. No. 4,952,739. A preferred embodiment utilizespolyisobutylene prepared from a pure isobutylene stream or a Raffinate Istream to prepare reactive isobutylene polymers with terminal vinylideneolefins. Polyisobutene polymers that may be employed are generally basedon a polymer chain of from 1500 to 3000.

The dispersant(s) are preferably non-polymeric (e.g., mono- orbis-succinimides). Such dispersants can be prepared by conventionalprocesses such as disclosed in U.S. Patent Application Publication No.2008/0020950, the disclosure of which is incorporated herein byreference.

The dispersant(s) can be borated by conventional means, as generallydisclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and 5,430,105.

Such dispersants may be used in an amount of about 0.01 to 20 weightpercent or 0.01 to 10 weight percent, preferably about 0.5 to 8 weightpercent, or more preferably 0.5 to 4 weight percent. Or such dispersantsmay be used in an amount of about 2 to 12 weight percent, preferablyabout 4 to 10 weight percent, or more preferably 6 to 9 weight percent.On an active ingredient basis, such additives may be used in an amountof about 0.06 to 14 weight percent, preferably about 0.3 to 6 weightpercent. The hydrocarbon portion of the dispersant atoms can range fromC₆₀ to C₁₀₀₀, or from C₇₀ to C₃₀₀, or from C₇₀ to C₂₀₀. Thesedispersants may contain both neutral and basic nitrogen, and mixtures ofboth. Dispersants can be end-capped by borates and/or cyclic carbonates.Nitrogen content in the finished oil can vary from about 200 ppm byweight to about 2000 ppm by weight, preferably from about 200 ppm byweight to about 1200 ppm by weight. Basic nitrogen can vary from about100 ppm by weight to about 1000 ppm by weight, preferably from about 100ppm by weight to about 600 ppm by weight.

As used herein, the dispersant concentrations are given on an “asdelivered” basis. Typically, the active dispersant is delivered with aprocess oil. The “as delivered” dispersant typically contains from about20 weight percent to about 80 weight percent, or from about 40 weightpercent to about 60 weight percent, of active dispersant in the “asdelivered” dispersant product.

Viscosity Modifiers

Viscosity modifiers (also known as viscosity index improvers (VIimprovers), and viscosity improvers) can be included in the lubricantcompositions of this disclosure.

Viscosity modifiers provide lubricants with high and low temperatureoperability. These additives impart shear stability at elevatedtemperatures and acceptable viscosity at low temperatures.

Suitable viscosity modifiers include high molecular weight hydrocarbons,polyesters and viscosity modifier dispersants that function as both aviscosity modifier and a dispersant. Typical molecular weights of thesepolymers are between about 10,000 to 1,500,000, more typically about20,000 to 1,200,000, and even more typically between about 50,000 and1,000,000.

Examples of suitable viscosity modifiers are linear or star-shapedpolymers and copolymers of methacrylate, butadiene, olefins, oralkylated styrenes. Polyisobutylene is a commonly used viscositymodifier. Another suitable viscosity modifier is polymethacrylate(copolymers of various chain length alkyl methacrylates, for example),some formulations of which also serve as pour point depressants. Othersuitable viscosity modifiers include copolymers of ethylene andpropylene, hydrogenated block copolymers of styrene and isoprene, andpolyacrylates (copolymers of various chain length acrylates, forexample). Specific examples include styrene-isoprene orstyrene-butadiene based polymers of 50,000 to 200,000 molecular weight.

Olefin copolymers are commercially available from Chevron OroniteCompany LLC under the trade designation “PARATONE®” (such as “PARATONE®8921” and “PARATONE® 8941”); from Afton Chemical Corporation under thetrade designation “HiTEC®” (such as “HiTEC® 5850B”; and from TheLubrizol Corporation under the trade designation “Lubrizol® 7067C”.Hydrogenated polyisoprene star polymers are commercially available fromInfineum International Limited, e.g., under the trade designation“SV200” and “SV600”. Hydrogenated diene-styrene block copolymers arecommercially available from Infineum International Limited, e.g., underthe trade designation “SV 50”.

The polymethacrylate or polyacrylate polymers can be linear polymerswhich are available from Evnoik Industries under the trade designation“Viscoplex®” (e.g., Viscoplex 6-954) or star polymers which areavailable from Lubrizol Corporation under the trade designation Asteric™(e.g., Lubrizol 87708 and Lubrizol 87725).

Illustrative vinyl aromatic-containing polymers useful in thisdisclosure may be derived predominantly from vinyl aromatic hydrocarbonmonomer. Illustrative vinyl aromatic-containing copolymers useful inthis disclosure may be represented by the following general formula:

A-B

wherein A is a polymeric block derived predominantly from vinyl aromatichydrocarbon monomer, and B is a polymeric block derived predominantlyfrom conjugated diene monomer.

In an embodiment of this disclosure, the viscosity modifiers may be usedin an amount of less than about 10 weight percent, preferably less thanabout 7 weight percent, more preferably less than about 4 weightpercent, and in certain instances, may be used at less than 2 weightpercent, preferably less than about 1 weight percent, and morepreferably less than about 0.5 weight percent, based on the total weightof the formulated oil or lubricating engine oil. Viscosity modifiers aretypically added as concentrates, in large amounts of diluent oil.

As used herein, the viscosity modifier concentrations are given on an“as delivered” basis. Typically, the active polymer is delivered with adiluent oil. The “as delivered” viscosity modifier typically containsfrom 20 weight percent to 75 weight percent of an active polymer forpolymethacrylate or polyacrylate polymers, or from 8 weight percent to20 weight percent of an active polymer for olefin copolymers,hydrogenated polyisoprene star polymers, or hydrogenated diene-styreneblock copolymers, in the “as delivered” polymer concentrate.

Antioxidants

Antioxidants retard the oxidative degradation of base oils duringservice. Such degradation may result in deposits on metal surfaces, thepresence of sludge, or a viscosity increase in the lubricant. Oneskilled in the art knows a wide variety of oxidation inhibitors that areuseful in lubricating oil compositions. See, Klamann in Lubricants andRelated Products, op cite, and U.S. Pat. Nos. 4,798,684 and 5,084,197,for example.

Useful antioxidants include hindered phenols. These phenolicantioxidants may be ashless (metal-free) phenolic compounds or neutralor basic metal salts of certain phenolic compounds. Typical phenolicantioxidant compounds are the hindered phenolics which are the oneswhich contain a sterically hindered hydroxyl group, and these includethose derivatives of dihydroxy aryl compounds in which the hydroxylgroups are in the o- or p-position to each other. Typical phenolicantioxidants include the hindered phenols substituted with C₆+ alkylgroups and the alkylene coupled derivatives of these hindered phenols.Examples of phenolic materials of this type 2-t-butyl-4-heptyl phenol;2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol;2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol;2-methyl-6-t-butyl-4-heptyl phenol; and 2-methyl-6-t-butyl-4-dodecylphenol. Other useful hindered mono-phenolic antioxidants may include forexample hindered 2,6-di-alkyl-phenolic proprionic ester derivatives.Bis-phenolic antioxidants may also be advantageously used in combinationwith the instant disclosure. Examples of ortho-coupled phenols include:2,2′-bis(4-heptyl-6-t-butyl-phenol); 2,2′-bis(4-octyl-6-t-butyl-phenol);and 2,2′-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenolsinclude for example 4,4′-bis(2,6-di-t-butyl phenol) and4,4′-methylene-bis(2,6-di-t-butyl phenol).

Effective amounts of one or more catalytic antioxidants may also beused. The catalytic antioxidants comprise an effective amount of a) oneor more oil soluble polymetal organic compounds; and, effective amountsof b) one or more substituted N,N′-diaryl-o-phenylenediamine compoundsor c) one or more hindered phenol compounds; or a combination of both b)and c). Catalytic antioxidants are more fully described in U.S. Pat. No.8,048,833, herein incorporated by reference in its entirety.

Non-phenolic oxidation inhibitors which may be used include aromaticamine antioxidants and these may be used either as such or incombination with phenolics. Typical examples of non-phenolicantioxidants include: alkylated and non-alkylated aromatic amines suchas aromatic monoamines of the formula R⁸R⁹R¹⁰N where R⁸ is an aliphatic,aromatic or substituted aromatic group, R⁹ is an aromatic or asubstituted aromatic group, and R¹⁰ is H, alkyl, aryl or R¹¹S(O)_(X)R¹²where R¹¹ is an alkylene, alkenylene, or aralkylene group, R¹² is ahigher alkyl group, or an alkenyl, aryl, or alkaryl group, and x is 0, 1or 2. The aliphatic group R⁸ may contain from 1 to about 20 carbonatoms, and preferably contains from about 6 to 12 carbon atoms. Thealiphatic group is a saturated aliphatic group. Preferably, both R⁸ andR⁹ are aromatic or substituted aromatic groups, and the aromatic groupmay be a fused ring aromatic group such as naphthyl. Aromatic groups R⁸and R⁹ may be joined together with other groups such as S.

Typical aromatic amines antioxidants have alkyl substituent groups of atleast about 6 carbon atoms. Examples of aliphatic groups include hexyl,heptyl, octyl, nonyl, and decyl. Generally, the aliphatic groups willnot contain more than about 14 carbon atoms. The general types of amineantioxidants useful in the present compositions include diphenylamines,phenyl naphthylamines, phenothiazines, imidodibenzyls and diphenylphenylene diamines. Mixtures of two or more aromatic amines are alsouseful. Polymeric amine antioxidants can also be used. Particularexamples of aromatic amine antioxidants useful in the present disclosureinclude: p,p′-dioctyldiphenylamine; t-octylphenyl-alpha-naphthylamine;phenyl-alphanaphthylamine; and p-octylphenyl-alpha-naphthylamine.

Sulfurized alkyl phenols and alkali or alkaline earth metal saltsthereof also are useful antioxidants.

Preferred antioxidants include hindered phenols, arylamines. Theseantioxidants may be used individually by type or in combination with oneanother. Such additives may be used in an amount of about 0.01 to 5weight percent, preferably about 0.01 to 1.5 weight percent, morepreferably zero to less than 1.5 weight percent, more preferably zero toless than 1 weight percent.

Pour Point Depressants (PPDs)

Conventional pour point depressants (also known as lube oil flowimprovers) may be added to the compositions of the present disclosure ifdesired. These pour point depressant may be added to lubricatingcompositions of the present disclosure to lower the minimum temperatureat which the fluid will flow or can be poured. Examples of suitable pourpoint depressants include polymethacrylates, polyacrylates,polyarylamides, condensation products of haloparaffin waxes and aromaticcompounds, vinyl carboxylate polymers, and terpolymers ofdialkylfumarates, vinyl esters of fatty acids and allyl vinyl ethers.U.S. Pat. Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655, 479;2,666,746; 2,721,877; 2,721,878; and 3,250,715 describe useful pourpoint depressants and/or the preparation thereof. Such additives may beused in an amount of about 0.01 to 5 weight percent, preferably about0.01 to 1.5 weight percent.

Seal Compatibility Agents

Seal compatibility agents help to swell elastomeric seals by causing achemical reaction in the fluid or physical change in the elastomer.Suitable seal compatibility agents for lubricating oils include organicphosphates, aromatic esters, aromatic hydrocarbons, esters (butylbenzylphthalate, for example), and polybutenyl succinic anhydride. Suchadditives may be used in an amount of about 0.01 to 3 weight percent,preferably about 0.01 to 2 weight percent.

Antifoam Agents

Anti-foam agents may advantageously be added to lubricant compositions.These agents retard the formation of stable foams. Silicones and organicpolymers are typical anti-foam agents. For example, polysiloxanes, suchas silicon oil or polydimethyl siloxane, provide antifoam properties.Anti-foam agents are commercially available and may be used inconventional minor amounts along with other additives such asdemulsifiers; usually the amount of these additives combined is lessthan 1 weight percent and often less than 0.1 weight percent.

Inhibitors and Antirust Additives

Antirust additives (or corrosion inhibitors) are additives that protectlubricated metal surfaces against chemical attack by water or othercontaminants. A wide variety of these are commercially available.

One type of antirust additive is a polar compound that wets the metalsurface preferentially, protecting it with a film of oil. Another typeof antirust additive absorbs water by incorporating it in a water-in-oilemulsion so that only the oil touches the metal surface. Yet anothertype of antirust additive chemically adheres to the metal to produce anon-reactive surface. Examples of suitable additives include zincdithiophosphates, metal phenolates, basic metal sulfonates, fatty acidsand amines. Such additives may be used in an amount of about 0.01 to 5weight percent, preferably about 0.01 to 1.5 weight percent.

Friction Modifiers

A friction modifier is any material or materials that can alter thecoefficient of friction of a surface lubricated by any lubricant orfluid containing such material(s). Friction modifiers, also known asfriction reducers, or lubricity agents or oiliness agents, and othersuch agents that change the ability of base oils, formulated lubricantcompositions, or functional fluids, to modify the coefficient offriction of a lubricated surface may be effectively used in combinationwith the base oils or lubricant compositions of the present disclosureif desired. Friction modifiers that lower the coefficient of frictionare particularly advantageous in combination with the base oils and lubecompositions of this disclosure.

Illustrative friction modifiers may include, for example, organometalliccompounds or materials, or mixtures thereof. Illustrative organometallicfriction modifiers useful in the lubricating engine oil formulations ofthis disclosure include, for example, molybdenum amine, molybdenumdiamine, an organotungstenate, a molybdenum dithiocarbamate, molybdenumdithiophosphates, molybdenum amine complexes, molybdenum carboxylates,and the like, and mixtures thereof. Similar tungsten based compounds maybe preferable.

Other illustrative friction modifiers useful in the lubricating engineoil formulations of this disclosure include, for example, alkoxylatedfatty acid esters, alkanolamides, polyol fatty acid esters, boratedglycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.

Illustrative alkoxylated fatty acid esters include, for example,polyoxyethylene stearate, fatty acid polyglycol ester, and the like.These can include polyoxypropylene stearate, polyoxybutylene stearate,polyoxyethylene isosterate, polyoxypropylene isostearate,polyoxyethylene palmitate, and the like.

Illustrative alkanolamides include, for example, lauric aciddiethylalkanolamide, palmic acid diethylalkanolamide, and the like.These can include oleic acid diethyalkanolamide, stearic aciddiethylalkanolamide, oleic acid diethylalkanolamide, polyethoxylatedhydrocarbylamides, polypropoxylated hydrocarbylamides, and the like.

Illustrative polyol fatty acid esters include, for example, glycerolmono-oleate, saturated mono-, di-, and tri-glyceride esters, glycerolmono-stearate, and the like. These can include polyol esters,hydroxyl-containing polyol esters, and the like.

Illustrative borated glycerol fatty acid esters include, for example,borated glycerol mono-oleate, borated saturated mono-, di-, andtri-glyceride esters, borated glycerol mono-sterate, and the like. Inaddition to glycerol polyols, these can include trimethylolpropane,pentaerythritol, sorbitan, and the like. These esters can be polyolmonocarboxylate esters, polyol dicarboxylate esters, and on occasionpolyoltricarboxylate esters. Preferred can be the glycerol mono-oleates,glycerol dioleates, glycerol trioleates, glycerol monostearates,glycerol distearates, and glycerol tristearates and the correspondingglycerol monopalmitates, glycerol dipalmitates, and glyceroltripalmitates, and the respective isostearates, linoleates, and thelike. On occasion the glycerol esters can be preferred as well asmixtures containing any of these. Ethoxylated, propoxylated, butoxylatedfatty acid esters of polyols, especially using glycerol as underlyingpolyol can be preferred.

Illustrative fatty alcohol ethers include, for example, stearyl ether,myristyl ether, and the like. Alcohols, including those that have carbonnumbers from C₃ to C₅₀, can be ethoxylated, propoxylated, or butoxylatedto form the corresponding fatty alkyl ethers. The underlying alcoholportion can preferably be stearyl, myristyl, C₁₁-C₁₃ hydrocarbon, oleyl,isosteryl, and the like.

The lubricating oils of this disclosure exhibit desired properties,e.g., wear control, in the presence or absence of a friction modifier.

Useful concentrations of friction modifiers may range from 0.01 weightpercent to 5 weight percent, or about 0.1 weight percent to about 2.5weight percent, or about 0.1 weight percent to about 1.5 weight percent,or about 0.1 weight percent to about 1 weight percent. Concentrations ofmolybdenum-containing materials are often described in terms of Mo metalconcentration. Advantageous concentrations of Mo may range from 25 ppmto 700 ppm or more, and often with a preferred range of 50-200 ppm.Friction modifiers of all types may be used alone or in mixtures withthe materials of this disclosure. Often mixtures of two or more frictionmodifiers, or mixtures of friction modifier(s) with alternate surfaceactive material(s), are also desirable.

When lubricating oil compositions contain one or more of the additivesdiscussed above, the additive(s) are blended into the composition in anamount sufficient for it to perform its intended function. Typicalamounts of such additives useful in the present disclosure are shown inTable 1 below.

It is noted that many of the additives are shipped from the additivemanufacturer as a concentrate, containing one or more additivestogether, with a certain amount of base oil diluents. Accordingly, theweight amounts in the table below, as well as other amounts mentionedherein, are directed to the amount of active ingredient (that is thenon-diluent portion of the ingredient). The weight percent (wt %)indicated below is based on the total weight of the lubricating oilcomposition.

TABLE 1 Typical Amounts of Other Lubricating Oil Components ApproximateApproximate Compound wt % (Useful) wt % (Preferred) Dispersant  0.1-200.1-8  Detergent  0.1-20 0.1-8  Friction Modifier 0.01-5  0.01-1.5Antioxidant 0.1-5  0.1-1.5 Pour Point Depressant (PPD) 0.0-5 0.01-1.5Anti-foam Agent 0.001-3  0.001-0.15 Viscosity Modifier 0.1-2 0.1-1 (solid polymer basis) Antiwear 0.2-3 0.5-1  Inhibitor and Antirust0.01-5  0.01-1.5

The foregoing additives are all commercially available materials. Theseadditives may be added independently but are usually precombined inpackages which can be obtained from suppliers of lubricant oiladditives. Additive packages with a variety of ingredients, proportionsand characteristics are available and selection of the appropriatepackage will take the requisite use of the ultimate composition intoaccount.

The following non-limiting examples are provided to illustrate thedisclosure.

EXAMPLES

Formulations were prepared as described herein. All of the ingredientsused herein are commercially available. Passenger vehicle engine oil(PVEO) formulations were prepared as described herein.

The antiwear additives used in the formulations were zinc stearate, tinstearate, sodium stearate, aluminum stearate, magnesium stearate,calcium stearate, silver stearate, palladium stearate, zincundecylenate, zinc oleate, and zinc napthenate.

The detergents used in the formulations were calcium salicylate andmagnesium sulfonate.

The additive package used in the formulations included conventionaladditives in conventional amounts. Conventional additives used in theformulations were one or more of an antioxidant, dispersant, pour pointdepressant, detergent, corrosion inhibitor, metal deactivator, sealcompatibility additive, anti-foam agent, inhibitor, anti-rust additive,and friction modifier.

A tribometer was used for measuring wear. A ball was held in areciprocating arm so that it was brought into contact with a flat disk.The flat disk and the ball were positioned inside a lubricant reservoirand sufficient lubricant is placed in the reservoir to cover the contactpoint between ball and disk. The reciprocating arm was reciprocated backand forth while maintaining contact between the ball and disk. Avariable weight was hung over the reciprocating arm thus allowing wearto be measured under different load conditions. In addition, the strokelength of the reciprocating arm can be varied as was the oil reservoirtemperature. Friction was measured with a load cell attached to thereciprocating arm.

Wear performance was evaluated as described above using a High FrequencyReciprocating Rig (HFRR) test. The HFRR is commercially available fromPCS Industries. The test equipment and procedure are similar to the ASTMD6079 method. The HFRR test conditions were as follows: temperature 100°C.; test duration 2 hours; stroke length 1 mm; frequency 10 Hz; and load400 grams. Wear was measured only on the disc. The ball is 6 mm diameterANSI E-52100 steel, Rockwell C hardness of 58-66. The disc is AISIE-52100 steel, Vickers HV30 hardness of ˜200.

The lubricant formulations used in the Examples are shown in Table 2below. The weight percent (wt %) indicated below is based on the totalweight of the lubricating oil composition.

TABLE 2 Lubricant Component Partial Formulation Full FormulationDescription (wt %) (wt %) Synthetic Base Oil Mixture 82.5-91.5 80.5-89.5Viscosity Modifier 0-5 0-5 Performance Additives System  9-10  9-10 ZDDP& Friction Modifiers 0 2 Additive of this Disclosure  0-1.5 0

Example 1

Zinc stearate was blended into polyalphaolefin (PAO 4) and tested in theHFRR. This wear test run was compared to a wear test run on PAO 4containing no additives. During the two hour duration of the HFRR test acontinuous measurement of friction between the ball and flat cylinderwas made. While friction changed during the duration of the test, thefriction measurement used herein was the average friction during thelast half hour of the test procedure. This number is referred to as theaverage friction. After the HFRR test was completed, the ball and diskwere removed from the tribometer. The topography (i.e., depth profile)of the wear scar produced at the center of the disk was measured with aprofilimeter. The depth of the elongated wear scar was measured alongthree lines across the wear scar. One profile was generated across thecenter of the wear scar, a second and third were measured to the rightand left of the wear scar center line. A single wear scar depth numberwas generated by taking the average depth achieved at the center of eachof the three profiles and averaging them.

The wear scar depth for the zinc stearate containing fluid is tabulatedbelow (Run 2) and compared to the wear scar depth for the PAO test (Run1). The data shows that zinc stearate reduced wear and friction whenadded to the lubricant base stock. It should be noted that when zincstearate is tested on its own in PAO basestock, due to the lowsolubility of zn stearate, the result can be variable and will depend ontime between blending and time of evaluation.

Wear Scar Test Antiwear Concentration Depth Average Number Additive(weight %) (Angstroms) Friction 1 None — 70000 0.53 80000 0.43 2 ZincStearate 1.5 26000 0.10

Example 2

Zinc stearate was tested in the HFRR in a lubricant blend containing amixture of detergent salts. The detergent salt mixture contained bothcalcium salicylate and magnesium sulfonate. The calcium salicylate is amixture of low, medium and high TBN salicylates. PAO 4 was used as thebase stock. PAO 4 is a non-polar paraffinic base stock. Profiles of thewear scar were generated as described above and the wear scar depth istabulated below.

Wear Scar Test Antiwear Concentration Concentration Depth Average NumberAdditive (weight %) Additive (weight %) (Angstroms) Friction 3 Zinc 1.5%Detergents 2-3% 4500 0.09 Stearate

A comparison of Run 3 containing zinc stearate and detergents to Runs 2(zinc stearate alone) and Run 1 (PAO alone) demonstrates that there is abeneficial reduction in wear and beneficial reduction in frictionresulting from the combination of zinc stearate and detergent (i.e.,calcium salicylate and magnesium sulfonate).

Example 3

Zinc stearate was tested in a partially formulated engine oil containinga full detergent and dispersant package of additives (but not containinga friction modifier or ZDDP) and tested in the HFRR (Run 4). A test wasalso run on the partial lubricant containing the detergent anddispersant package alone (Run 5). Wear scars were profiled as describedabove and the wear scar depths are tabulated below. The data demonstratethat even when blended into a full detergent and dispersant package withother additives typically used in lubricants, but not containing afriction modifier or ZDDP, the addition of zinc stearate reduces wearand friction. The detergent concentration of the partial formulation wasbetween 2-3% by weight containing a mixture of calcium salicylates andmagnesium sulfonate.

Wear Scar Test Antiwear Concentration Depth Average Number Additive(weight %) (Angstroms) Friction 4 Zn Stearate 1.5% 4500 0.08 5 None —36000 0.15

Example 4

HFRR tests were run to compare the antiwear performance of zinc stearatewith other metal stearates. In this series of tests, each stearate wasblended into the partial lubricant formulation containing a fullyformulated engine oil detergent and dispersant additive formulation (notcontaining a friction modifier or ZDDP). Each lubricant and one of thestearates were evaluated in the HFRR test and the wear scars wereevaluated as described above. Wear scar depths are tabulated below. Insome cases, data represents averages of several experiments.

Wear Scar Test Antiwear Concentration Depth Average Number Additive(weight %) (Angstroms) Friction 4 Zinc Stearate 1.5% 4500 0.08 5 None —36000 0.15 6 Silver Stearate 0.62% 4000 0.08 7 Palladium 1.06% 4000 0.08Stearate 8 Tin Stearate 1.5% 7000 0.09 9 Sodium Stearate 1.5% 15000 0.1010 Aluminum 1.5% 17000 0.14 Stearate 11 Magnesium 1.5% 22500 0.18Stearate 12 Calcium Stearate 1.5% 23000 0.17

The data shows that zinc stearate had the best wear and frictionperformance. The data also shows that other stearates reduced wear andfriction to differing levels of effectiveness.

Example 5

Different zinc carboxylate salts were tested in the HFRR. Theserepresent salts of zinc and different carboxylate anions. The testingresults are tabulated in FIG. 3.

The data in FIG. 3 demonstrates that straight chain carboxylates havebetter performance than non-straight chains as indicated by runs 4 (zincstearate), 13 (zinc undecylenate) and 14 (zinc oleate) compared with run15 (zinc napthenate) which is not a straight chain. Better performancewas achieved with the stearate which is a saturated straight chain of 18carbons.

Engine testing was also conducted for formulations of this disclosure.The engine testing included measurements of the following parameters:IIIG kinematic viscosity increase at 40° C. (%) as measured by ASTMD7320 (lower value is better); IIIG average weighted piston deposits(merits) as measured by ASTM D7320 (higher value is better); IIIGaverage cam and lifter wear (μm) as measured by ASTM D7320 (lower valueis better); IIIG average piston skirt varnish (merits) as measured byASTM D7320 (higher value is better); IIIG oil ring land deposit (merits)as measured by ASTM D7320 (higher value is better); IIIG undercrown(merits) as measured by ASTM D7320 (higher value is better); IIIG groove1 as measured by ASTM D7320 (higher value is better); IIIG groove 2 asmeasured by ASTM D7320 (higher value is better); IIIG groove 3 asmeasured by ASTM D7320 (higher value is better); and IIIG land 2 asmeasured by ASTM D7320 (higher value is better).

Example 6

The lubricants used in HFRR run 4 and run 5 were tested in a sequenceIIIG engine test as described above. The results of sequence IIIG enginetesting are tabulated below. The results demonstrate that the additionof zinc stearate to the lubricant reduced wear, reduced engine depositsand improved the oxidative stability of the lubricant.

Oil From Run 4 (Contains Zn Stearate) Oil From Run 5 Average PistonSkirt Varnish 9.79 9.40 Weighted Piston Deposit 6.92 4.15 Cam & LifterWear (microns) 35.1 343.8 Viscosity Increase (percent) 44.1 246 Oil RingLand Deposit 8.11 4.27 (merit rating) Piston Undercrown Deposit 8.633.27 (merit rating) Piston Groove 1 (merit rating) 1.91 1.46 PistonGroove 2 (merit rating) 3.50 1.01 Piston Groove 3 (merit rating) 9.516.33 Piston Land 2 (merit rating) 1.97 1.08 Merit ratings: 0-10 (10 =Clean)

Antiwear performance is indicated by the low cam and lifter wear resultachieved for the Run 4 oil containing zinc stearate. Improved oxidationcontrol is indicated by the low viscosity increase. Oxidation is asignificant contributor to oil thickening and viscosity increase.Improved engine deposit control is indicated by the high merit ratingsachieved for various piston deposits. Higher merit ratings indicatelower deposits and cleaner pistons.

FIGS. 1-3 depict results from testing carried out in Examples 1-6.

FIG. 1 (top) shows the performance in one experiment of the partialformulation in which ZDDP and friction modifiers were removed (“partial”formulation). FIG. 1 (bottom) shows performance in one experiment forthe full formulation. FIG. 1 (top and bottom) contain three lines. Eachline is a depth profile of the final wear scar across the center, rightand left of the oval shaped scar. The absence of ZDDP results in adeeper scar.

FIG. 2 shows the wear scar data generated when zinc stearate was addedto the “partial” formulation. The three lines represent depth profilesof the final wear scar in the center, right and left of the scar. Thedepth of this wear scar is less than the full formulation shown in FIG.1.

FIG. 3 shows the results of HFRR testing for other metal carboxylatesalts in addition to zinc stearate in FIG. 2. Some results are averagesover several experiments.

Example 7

Lubricating oils were blended with varying concentrations of zincstearate and salicylate detergents (Ca and Mg with component Total BaseNumbers of 70, 342 and 350) to form inventive lubricating oils. The basestock used for all the inventive and comparative blends included 95 wt %PAO-4 and 5 wt % of alkylated naphthalene. The lubricating oils werealso blended with varying concentrations of zinc stearate and sulfonatedetergents (Ca and Mg with component Total Base Numbers of 8, 300 and400) to form comparative lubricating oils. The comparative and inventivelubricating oils did not include any other lubricating oil additives.The comparative and inventive lubricating oils were tested for averagefriction and average wear using the HFRR method described above. FIG. 4is a plot of average friction versus the ratio of moles of detergentmetal (Ca, Mg) divided by the total moles of zinc from zinc stearate forboth salicylate detergents (inventive) and sulfonate detergents(comparative). FIG. 5 is a plot of average wear versus the ratio ofmoles of detergent metal (Ca, Mg) divided by the total moles of zincfrom zinc stearate for both salicylate detergents (inventive) andsulfonate detergents (comparative). The results in FIG. 4 indicate thatthere was a synergy for both Ca salicylate and Mg salicylate detergentsfor improving average friction when used in combination with zincstearate. At a Ca/Zn ratio of 0.37 and higher there was a frictionsynergy. We are comparing to a reference point of basestock alone wherefriction is 0.16 (zero on the x-axis). The results in FIG. 5 alsoindicate that there was a synergy for the Ca salicylate detergent forimproving average wear when used in combination with zinc stearate.

While not wishing to be bound to any particular theory, it is believedthat the antiwear performance of the formulations of this disclosure isunexpectedly enhanced by an interaction between zinc stearate and othermolecules in the additive formulation. One example of this is theinteraction of antiwear with the detergents (i.e., salicylate).

The lubricants of this disclosure are low in sulfur and are lesscorrosive toward iron than antiwear additives containing sulfur. Onemanifestation of this is that the present disclosure is less likely tocorrode ferrous materials (e.g., steel) to produce iron sulfide.

PCT and EP Clauses:

1. A method for improving wear control, while maintaining or improvingfuel efficiency, in an engine or other mechanical component lubricatedwith a lubricating oil by using as the lubricating oil a formulated oil,said formulated oil having a composition comprising a lubricating oilbase stock as a major component; and a mixture as a minor component of(i) at least one metal salt of a straight chain carboxylic acid, whereinthe metal is selected from the group consisting of palladium (Pd),silver (Ag), gold (Au), zinc (Zn), and combinations thereof, and (ii) atleast one metal salicylate salt, wherein the metal is calcium (Ca),magnesium (Mg) or combinations thereof; wherein the molar ratio of thetotal metal concentration from the salicylate salt divided by the totalmetal concentration from the straight chain carboxylic acid ranges from0.1 to 40; and wherein wear control is improved and fuel efficiency ismaintained or improved as compared to wear control and fuel efficiencyachieved using a lubricating oil containing a minor component other thanthe mixture of the at least one metal salt of a straight chaincarboxylic acid and the at least one metal salicylate salt.

2. The method of clause 1 wherein the lubricating oil base stockcomprises a Group I, Group II, Group III, Group IV or Group V base oil.

3. The method of clauses 1-2 wherein the straight chain carboxylic acidis an aliphatic, saturated, unbranched carboxylic acid having from 8 to26 carbon atoms, and mixtures thereof.

4. The method of clauses 1-3 wherein the at least one metal salt of thestraight chain carboxylic acid comprises zinc stearate, silver stearate,palladium stearate, zinc palmitate, silver palmitate, palladiumpalmitate, or mixtures thereof.

5. The method of clauses 1-4 wherein the at least one metal salt of thestraight chain carboxylic acid is present in an amount of from 0.01weight percent to 5 weight percent, based on the total weight of theformulated oil.

6. The method of clauses 1-5 wherein the at least one metal salicylatesalt is present in an amount of from 0.01 weight percent to 5 weightpercent, based on the total weight of the formulated oil.

7. The method of clauses 1-6 wherein the lubricating oil base stock ispresent in an amount of from 70 weight percent to 95 weight percent,based on the total weight of the formulated oil.

8. The method of clauses 1-7 wherein the formulated oil furthercomprises one or more of an antiwear additive, viscosity modifier,antioxidant, detergent, other dispersant, pour point depressant,corrosion inhibitor, metal deactivator, seal compatibility additive,anti-foam agent, inhibitor, and anti-rust additive.

9. A lubricating oil having a composition comprising a lubricating oilbase stock as a major component; and a mixture as a minor component of(i) at least one metal salt of a straight chain carboxylic acid, whereinthe metal is selected from the group consisting of palladium (Pd),silver (Ag), gold (Au), zinc (Zn), and combinations thereof, and (ii) atleast one metal salicylate salt, wherein the metal is calcium (Ca),magnesium (Mg) or combinations thereof; wherein the molar ratio of thetotal metal concentration from the salicylate salt divided by the totalmetal concentration from the straight chain carboxylic acid ranges from0.1 to 40; and wherein wear control is improved and fuel efficiency ismaintained or improved as compared to wear control and fuel efficiencyachieved using a lubricating oil containing a minor component other thanthe mixture of the at least one metal salt of a straight chaincarboxylic acid and the at least one metal salicylate salt.

10. The lubricating oil of clause 9 wherein the lubricating oil basestock comprises a Group I, Group II, Group III, Group IV or Group V baseoil.

11. The lubricating oil of clauses 9-10 wherein the straight chaincarboxylic acid is an aliphatic, saturated, unbranched carboxylic acidhaving from 8 to 26 carbon atoms, and mixtures thereof.

12. The lubricating oil of clauses 9-11 wherein the at least one metalsalt of the straight chain carboxylic acid comprises zinc stearate,silver stearate, palladium stearate, zinc palmitate, silver palmitate,palladium palmitate, or mixtures thereof.

13. The lubricating oil of clauses 9-12 wherein the at least one metalsalt of the straight chain carboxylic acid is present in an amount offrom 0.01 weight percent to 5 weight percent, based on the total weightof the formulated oil.

14. The lubricating oil of clauses 9-13 wherein the at least one metalsalicylate salt is present in an amount of from 0.01 weight percent to 5weight percent, based on the total weight of the formulated oil.

15. The lubricating oil of clauses 9-14 wherein the lubricating oil basestock is present in an amount of from 70 weight percent to 95 weightpercent, based on the total weight of the formulated oil.

16. The lubricating oil of clauses 9-15 wherein the formulated oilfurther comprises one or more of an antiwear additive, viscositymodifier, antioxidant, detergent, other dispersant, pour pointdepressant, corrosion inhibitor, metal deactivator, seal compatibilityadditive, anti-foam agent, inhibitor, and anti-rust additive.

17. The lubricating oil of clauses 9-16 which is a passenger vehicleengine oil (PVEO).

All patents and patent applications, test procedures (such as ASTMmethods, UL methods, and the like), and other documents cited herein arefully incorporated by reference to the extent such disclosure is notinconsistent with this disclosure and for all jurisdictions in whichsuch incorporation is permitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.While the illustrative embodiments of the disclosure have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of thedisclosure. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present disclosure,including all features which would be treated as equivalents thereof bythose skilled in the art to which the disclosure pertains.

The present disclosure has been described above with reference tonumerous embodiments and specific examples. Many variations will suggestthemselves to those skilled in this art in light of the above detaileddescription. All such obvious variations are within the full intendedscope of the appended claims.

1. A method for improving wear control, while maintaining or improvingfuel efficiency, in an engine or other mechanical component lubricatedwith a lubricating oil by using as the lubricating oil a formulated oil,said formulated oil having a composition comprising a lubricating oilbase stock as a major component; and a mixture as a minor component of(i) at least one metal salt of a straight chain carboxylic acid, whereinthe metal is selected from the group consisting of palladium (Pd),silver (Ag), gold (Au), zinc (Zn), and combinations thereof, and (ii) atleast one metal salicylate salt, wherein the metal is calcium (Ca),magnesium (Mg) or combinations thereof, wherein the molar ratio of thetotal metal concentration from the salicylate salt divided by the totalmetal concentration from the straight chain carboxylic acid ranges from0.1 to 40; and wherein wear control is improved and fuel efficiency ismaintained or improved as compared to wear control and fuel efficiencyachieved using a lubricating oil containing a minor component other thanthe mixture of the at least one metal salt of a straight chaincarboxylic acid and the at least one metal salicylate salt.
 2. Themethod of claim 1 wherein the lubricating oil base stock comprises aGroup I, Group II, Group III, Group IV or Group V base oil.
 3. Themethod of claim 1 wherein the straight chain carboxylic acid is analiphatic, saturated, unbranched carboxylic acid having from 8 to 26carbon atoms, and mixtures thereof.
 4. The method of claim 1 wherein thestraight chain carboxylic acid is palmitic acid (C16), stearic acid(C18), or combinations thereof.
 5. The method of claim 1 wherein the atleast one metal salt of the straight chain carboxylic acid compriseszinc stearate, silver stearate, palladium stearate, zinc palmitate,silver palmitate, palladium palmitate, or mixtures thereof.
 6. Themethod of claim 1 wherein the at least one metal salt of the straightchain carboxylic acid is present in an amount of from 0.01 weightpercent to 5 weight percent, based on the total weight of the formulatedoil.
 7. The method of claim 1 wherein the at least one metal salicylatesalt is present in an amount of from 0.01 weight percent to 5 weightpercent, based on the total weight of the formulated oil.
 8. The methodof claim 1 wherein the lubricating oil base stock is present in anamount of from 70 weight percent to 95 weight percent, based on thetotal weight of the formulated oil.
 9. The method of claim 1 wherein theformulated oil further comprises one or more of an antiwear additive,viscosity modifier, antioxidant, detergent, other dispersant, pour pointdepressant, corrosion inhibitor, metal deactivator, seal compatibilityadditive, anti-foam agent, inhibitor, and anti-rust additive.
 10. Themethod of claim 1, wherein the at least one metal salt of the straightchain carboxylic acid comprises zinc stearate.
 11. The method of claim10, wherein the at least one metal salicylate salt is calciumsalicylate.
 12. The method of claim 11, wherein the molar ratio of thetotal metal concentration from the salicylate salt divided by the totalmetal concentration from the straight chain carboxylic acid ranges from0.4 to
 10. 13. A lubricating oil having a composition comprising alubricating oil base stock as a major component; and a mixture as aminor component of (i) at least one metal salt of a straight chaincarboxylic acid, wherein the metal is selected from the group consistingof palladium (Pd), silver (Ag), gold (Au), zinc (Zn), and combinationsthereof, and (ii) at least one metal salicylate salt, wherein the metalis calcium (Ca), magnesium (Mg) or combinations thereof; wherein themolar ratio of the total metal concentration from the salicylate saltdivided by the total metal concentration from the straight chaincarboxylic acid ranges from 0.1 to 40; and wherein wear control isimproved and fuel efficiency is maintained or improved as compared towear control and fuel efficiency achieved using a lubricating oilcontaining a minor component other than the mixture of the at least onemetal salt of a straight chain carboxylic acid and the at least onemetal salicylate salt.
 14. The lubricating oil of claim 13 wherein thelubricating oil base stock comprises a Group I, Group II, Group III,Group IV or Group V base oil.
 15. The lubricating oil of claim 13wherein the straight chain carboxylic acid is an aliphatic, saturated,unbranched carboxylic acid having from 8 to 26 carbon atoms, andmixtures thereof.
 16. The lubricating oil of claim 13 wherein thestraight chain carboxylic acid is palmitic acid (C16), stearic acid(C18), or combinations thereof.
 17. The lubricating oil of claim 13wherein the at least one metal salt of the straight chain carboxylicacid comprises zinc stearate, silver stearate, palladium stearate, zincpalmitate, silver palmitate, palladium palmitate, and mixtures thereof.18. The lubricating oil of claim 13 wherein the at least one metal saltof the straight chain carboxylic acid is present in an amount of from0.01 weight percent to 5 weight percent, based on the total weight ofthe formulated oil.
 19. The lubricating oil of claim 13 wherein the atleast one metal salicylate salt is present in an amount of from 0.01weight percent to 5 weight percent, based on the total weight of theformulated oil.
 20. The lubricating oil of claim 13 wherein thelubricating oil base stock is present in an amount of from 70 weightpercent to 95 weight percent, based on the total weight of theformulated oil.
 21. The lubricating oil of claim 13 further comprisingone or more of an antiwear additive, other viscosity modifiers,antioxidant, detergent, other dispersant, pour point depressant,corrosion inhibitor, metal deactivator, seal compatibility additive,anti-foam agent, inhibitor, and anti-rust additive.
 22. The lubricatingoil of claim 13, wherein the at least one metal salt of the straightchain carboxylic acid comprises zinc stearate.
 23. The lubricating oilof claim 22, wherein the at least one metal salicylate salt is calciumsalicylate.
 24. The lubricating oil of claim 23, wherein the molar ratioof the total metal concentration from the salicylate salt divided by thetotal metal concentration from the straight chain carboxylic acid rangesfrom 0.4 to
 10. 25. The lubricating oil of claim 13 which is a passengervehicle engine oil (PVEO).